Pull request project-chip#94: Initial CODEOWNERS file

Merge in WMN_TOOLS/matter from add_code_owner_file to silabs

Squashed commit of the following:

commit 797843ebba64a63e96341520785581e2dea0bd55
Author: jepenven-silabs <jean-francois.penven@silabs.com>
Date:   Tue Sep 13 13:58:56 2022 -0400

    Initial CODEOWNER file

CODEOWNERS

@@ -0,0 +1,26 @@
+@@@MatterCSA @jumartin @jepenven @ricasall @makardou @selissia
+@@@MatterWatt @jumartin @jepenven @ricasall @makardou @selissia @rerasool
+@@@MatterWifi @mamehta
+@@@Documentation @wehale @caowens @rerasool
+@@@Unify @anesbens @dejensen @thbowley @dewassie @svradema
+@@@CICD @gbash @yushu @shmakdis @jepenven
+
+# Pipeline rule
+./Jenkinsfile @@MatterWatt @@CICD
+./silabs_ci_scripts/ @@MatterWatt @@CICD
+
+# Documentation is everyone business
+**/*.md @@Documentation @@MatterWatt @@MatterWifi @@Unify
+
+./examples/ @@MatterCSA
+./src/ @@MatterCSA
+
+./silabs_examples @@MatterWatt @@MatterWifi
+
+./silabs_examples/unify-matter-bridge @@Unify @@MatterWatt
+
+CODEOWNERS               @@MatterWatt
+
+# At least a senior and two code owners in total must approve.
+OverallCheck(2)
+Check(@@MatterCSA >= 1)