releasenotes: update with doc issues addressed

Add documentation changes with this release

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
diff --git a/doc/release-notes-1.12.rst b/doc/release-notes-1.12.rst
index 2f79a85..3daaaed 100644
--- a/doc/release-notes-1.12.rst
+++ b/doc/release-notes-1.12.rst
@@ -108,7 +108,7 @@
 * Add PRIORITY support to net_context. This is working same way as SO_PRIORITY
   in BSD sockets API.
 * Add network traffic classification support to Rx and Tx paths. This allows
-  priorization of incoming or outgoing network traffic. Both Rx and Tx can
+  prioritization of incoming or outgoing network traffic. Both Rx and Tx can
   have max 8 network queues.
 * Add network interface up/down command to net-shell.
 * Create ethernet driver for native_posix board. The driver is enabled
@@ -186,7 +186,13 @@
 
 Documentation
 *************
+
 * Added description for kernel test cases
+* Discovered some API docs were missing, and fixed
+* Documented writing guidelines and local doc generation process
+* Improved Sphinx search results output (removed markup)
+* Improved configuration options auto-generated documentation
+* Significantly reduced local doc regeneration time
 
 Tests and Samples
 *****************