doc: move kernel docs as a main chapter

Move the kernel documentation up and make it a main chapter. Right now
it is hidden very low in the structure under references.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
diff --git a/CODEOWNERS b/CODEOWNERS
index e6419b2..ca14a7c 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -812,5 +812,5 @@
 /tests/subsys/shell/                      @jakub-uC @nordic-krch
 # Get all docs reviewed
 *.rst                                     @nashif
-/doc/reference/kernel/                    @andyross @nashif
+/doc/kernel/                              @andyross @nashif
 *posix*.rst                               @aescolar @daor-oti
diff --git a/MAINTAINERS.yml b/MAINTAINERS.yml
index b44e3af..ce146b2 100644
--- a/MAINTAINERS.yml
+++ b/MAINTAINERS.yml
@@ -1071,7 +1071,7 @@
         - dcpleung
         - peter-mitsis
     files:
-        - doc/reference/kernel/
+        - doc/kernel/
         - include/kernel*.h
         - kernel/
         - tests/kernel/
diff --git a/doc/index-tex.rst b/doc/index-tex.rst
index 19fed0d..9d9c094 100644
--- a/doc/index-tex.rst
+++ b/doc/index-tex.rst
@@ -16,6 +16,7 @@
    introduction/index.rst
    getting_started/index.rst
    contribute/index.rst
+   kernel/index.rst
    development_process/index.rst
    guides/build/index.rst
    application/index.rst
diff --git a/doc/index.rst b/doc/index.rst
index b43a7ea..569407d 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -107,6 +107,7 @@
    development_process/index.rst
    guides/build/index.rst
    application/index.rst
+   kernel/index.rst
    reference/index.rst
    guides/index.rst
    security/index.rst
diff --git a/doc/reference/kernel/data_passing/fifos.rst b/doc/kernel/data_passing/fifos.rst
similarity index 100%
rename from doc/reference/kernel/data_passing/fifos.rst
rename to doc/kernel/data_passing/fifos.rst
diff --git a/doc/reference/kernel/data_passing/lifos.rst b/doc/kernel/data_passing/lifos.rst
similarity index 100%
rename from doc/reference/kernel/data_passing/lifos.rst
rename to doc/kernel/data_passing/lifos.rst
diff --git a/doc/reference/kernel/data_passing/mailboxes.rst b/doc/kernel/data_passing/mailboxes.rst
similarity index 100%
rename from doc/reference/kernel/data_passing/mailboxes.rst
rename to doc/kernel/data_passing/mailboxes.rst
diff --git a/doc/reference/kernel/data_passing/message_queues.rst b/doc/kernel/data_passing/message_queues.rst
similarity index 100%
rename from doc/reference/kernel/data_passing/message_queues.rst
rename to doc/kernel/data_passing/message_queues.rst
diff --git a/doc/reference/kernel/data_passing/pipes.rst b/doc/kernel/data_passing/pipes.rst
similarity index 100%
rename from doc/reference/kernel/data_passing/pipes.rst
rename to doc/kernel/data_passing/pipes.rst
diff --git a/doc/reference/kernel/data_passing/queues.rst b/doc/kernel/data_passing/queues.rst
similarity index 100%
rename from doc/reference/kernel/data_passing/queues.rst
rename to doc/kernel/data_passing/queues.rst
diff --git a/doc/reference/kernel/data_passing/stacks.rst b/doc/kernel/data_passing/stacks.rst
similarity index 100%
rename from doc/reference/kernel/data_passing/stacks.rst
rename to doc/kernel/data_passing/stacks.rst
diff --git a/doc/reference/kernel/index.rst b/doc/kernel/index.rst
similarity index 100%
rename from doc/reference/kernel/index.rst
rename to doc/kernel/index.rst
diff --git a/doc/reference/kernel/memory/heap.rst b/doc/kernel/memory/heap.rst
similarity index 100%
rename from doc/reference/kernel/memory/heap.rst
rename to doc/kernel/memory/heap.rst
diff --git a/doc/reference/kernel/memory/slabs.rst b/doc/kernel/memory/slabs.rst
similarity index 100%
rename from doc/reference/kernel/memory/slabs.rst
rename to doc/kernel/memory/slabs.rst
diff --git a/doc/reference/kernel/other/atomic.rst b/doc/kernel/other/atomic.rst
similarity index 100%
rename from doc/reference/kernel/other/atomic.rst
rename to doc/kernel/other/atomic.rst
diff --git a/doc/reference/kernel/other/cpu_idle.rst b/doc/kernel/other/cpu_idle.rst
similarity index 100%
rename from doc/reference/kernel/other/cpu_idle.rst
rename to doc/kernel/other/cpu_idle.rst
diff --git a/doc/reference/kernel/other/cxx_support.rst b/doc/kernel/other/cxx_support.rst
similarity index 100%
rename from doc/reference/kernel/other/cxx_support.rst
rename to doc/kernel/other/cxx_support.rst
diff --git a/doc/reference/kernel/other/fatal.rst b/doc/kernel/other/fatal.rst
similarity index 100%
rename from doc/reference/kernel/other/fatal.rst
rename to doc/kernel/other/fatal.rst
diff --git a/doc/reference/kernel/other/float.rst b/doc/kernel/other/float.rst
similarity index 100%
rename from doc/reference/kernel/other/float.rst
rename to doc/kernel/other/float.rst
diff --git a/doc/reference/kernel/other/interrupts.rst b/doc/kernel/other/interrupts.rst
similarity index 100%
rename from doc/reference/kernel/other/interrupts.rst
rename to doc/kernel/other/interrupts.rst
diff --git a/doc/reference/kernel/other/polling.rst b/doc/kernel/other/polling.rst
similarity index 100%
rename from doc/reference/kernel/other/polling.rst
rename to doc/kernel/other/polling.rst
diff --git a/doc/reference/kernel/other/thread_local_storage.rst b/doc/kernel/other/thread_local_storage.rst
similarity index 100%
rename from doc/reference/kernel/other/thread_local_storage.rst
rename to doc/kernel/other/thread_local_storage.rst
diff --git a/doc/reference/kernel/other/version.rst b/doc/kernel/other/version.rst
similarity index 100%
rename from doc/reference/kernel/other/version.rst
rename to doc/kernel/other/version.rst
diff --git a/doc/reference/kernel/scheduling/cooperative.svg b/doc/kernel/scheduling/cooperative.svg
similarity index 100%
rename from doc/reference/kernel/scheduling/cooperative.svg
rename to doc/kernel/scheduling/cooperative.svg
diff --git a/doc/reference/kernel/scheduling/index.rst b/doc/kernel/scheduling/index.rst
similarity index 100%
rename from doc/reference/kernel/scheduling/index.rst
rename to doc/kernel/scheduling/index.rst
diff --git a/doc/reference/kernel/scheduling/preemptive.svg b/doc/kernel/scheduling/preemptive.svg
similarity index 100%
rename from doc/reference/kernel/scheduling/preemptive.svg
rename to doc/kernel/scheduling/preemptive.svg
diff --git a/doc/reference/kernel/scheduling/timeslicing.svg b/doc/kernel/scheduling/timeslicing.svg
similarity index 100%
rename from doc/reference/kernel/scheduling/timeslicing.svg
rename to doc/kernel/scheduling/timeslicing.svg
diff --git a/doc/reference/kernel/smp/smp.rst b/doc/kernel/smp/smp.rst
similarity index 100%
rename from doc/reference/kernel/smp/smp.rst
rename to doc/kernel/smp/smp.rst
diff --git a/doc/reference/kernel/smp/smpinit.svg b/doc/kernel/smp/smpinit.svg
similarity index 100%
rename from doc/reference/kernel/smp/smpinit.svg
rename to doc/kernel/smp/smpinit.svg
diff --git a/doc/reference/kernel/synchronization/condvar.rst b/doc/kernel/synchronization/condvar.rst
similarity index 100%
rename from doc/reference/kernel/synchronization/condvar.rst
rename to doc/kernel/synchronization/condvar.rst
diff --git a/doc/reference/kernel/synchronization/events.rst b/doc/kernel/synchronization/events.rst
similarity index 100%
rename from doc/reference/kernel/synchronization/events.rst
rename to doc/kernel/synchronization/events.rst
diff --git a/doc/reference/kernel/synchronization/mutexes.rst b/doc/kernel/synchronization/mutexes.rst
similarity index 100%
rename from doc/reference/kernel/synchronization/mutexes.rst
rename to doc/kernel/synchronization/mutexes.rst
diff --git a/doc/reference/kernel/synchronization/semaphores.rst b/doc/kernel/synchronization/semaphores.rst
similarity index 100%
rename from doc/reference/kernel/synchronization/semaphores.rst
rename to doc/kernel/synchronization/semaphores.rst
diff --git a/doc/reference/kernel/threads/index.rst b/doc/kernel/threads/index.rst
similarity index 100%
rename from doc/reference/kernel/threads/index.rst
rename to doc/kernel/threads/index.rst
diff --git a/doc/reference/kernel/threads/nothread.rst b/doc/kernel/threads/nothread.rst
similarity index 100%
rename from doc/reference/kernel/threads/nothread.rst
rename to doc/kernel/threads/nothread.rst
diff --git a/doc/reference/kernel/threads/priorities.svg b/doc/kernel/threads/priorities.svg
similarity index 100%
rename from doc/reference/kernel/threads/priorities.svg
rename to doc/kernel/threads/priorities.svg
diff --git a/doc/reference/kernel/threads/system_threads.rst b/doc/kernel/threads/system_threads.rst
similarity index 100%
rename from doc/reference/kernel/threads/system_threads.rst
rename to doc/kernel/threads/system_threads.rst
diff --git a/doc/reference/kernel/threads/thread_states.svg b/doc/kernel/threads/thread_states.svg
similarity index 100%
rename from doc/reference/kernel/threads/thread_states.svg
rename to doc/kernel/threads/thread_states.svg
diff --git a/doc/reference/kernel/threads/workqueue.rst b/doc/kernel/threads/workqueue.rst
similarity index 100%
rename from doc/reference/kernel/threads/workqueue.rst
rename to doc/kernel/threads/workqueue.rst
diff --git a/doc/reference/kernel/timing/clocks.rst b/doc/kernel/timing/clocks.rst
similarity index 100%
rename from doc/reference/kernel/timing/clocks.rst
rename to doc/kernel/timing/clocks.rst
diff --git a/doc/reference/kernel/timing/timers.rst b/doc/kernel/timing/timers.rst
similarity index 100%
rename from doc/reference/kernel/timing/timers.rst
rename to doc/kernel/timing/timers.rst
diff --git a/doc/reference/index.rst b/doc/reference/index.rst
index 4a40ac7..b0ef7a6 100644
--- a/doc/reference/index.rst
+++ b/doc/reference/index.rst
@@ -20,7 +20,6 @@
    file_system/index.rst
    iterable_sections/index.rst
    misc/formatted_output.rst
-   kernel/index.rst
    libc/index.rst
    logging/index.rst
    memory_management/index.rst