.github: make core team codeowners (#6383)

Expanding the list of people who can sign off on reviews.

.github/CODEOWNERS

@@ -7,17 +7,5 @@
 # global owners are only requested if there isn't a more specific
 # codeowner specified below. For this reason, the global codeowners
 # are often repeated in package-level definitions.
-*       @alexanderbez @ebuchman @tessr
+*       @alexanderbez @ebuchman @cmwaters @tessr @tychoish
 
-# Overrides for tooling packages
-.github/ @marbar3778 @alexanderbez @ebuchman @tessr
-DOCKER/ @marbar3778 @alexanderbez @ebuchman @tessr
-
-# Overrides for core Tendermint packages
-abci/  @marbar3778 @alexanderbez @ebuchman @tessr @tychoish
-evidence/ @cmwaters @ebuchman @tessr @tychoish
-light/ @cmwaters @ebuchman @tessr @tychoish
-
-# Overrides for docs
-*.md @marbar3778 @alexanderbez @ebuchman @tessr
-docs/ @marbar3778 @alexanderbez @ebuchman @tessr