Create CODEOWNERS

Add a CODEOWNERS files to assign ownership to different parts of the code base

.github/CODEOWNERS

diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
new file mode 100644
index 0000000..5436e2c
--- /dev/null
+++ b/.github/CODEOWNERS
@@ -0,0 +1,2 @@
+# Default owner
+* @aardappel @dbaileychess derekbailey@google.com