Update codeowners (#455)

This PR updates the primary codeowners from `team-app-platform-product`
to `team-automation`.

Author: ldhenry

CODEOWNERS

@@ -1,12 +1,12 @@
 # https://help.github.com/en/github/creating-cloning-and-archiving-repositories/about-code-owners
 
-* @launchdarkly/team-app-platform-product
+* @launchdarkly/team-automation
 
 # Documentation
 *.md @launchdarkly/team-docs
 
 # vendor docs don't need to be owned by docs team
-vendor/ @launchdarkly/team-app-platform-product
+vendor/ @launchdarkly/team-automation
 
 # Change log is updated by release bot
-CHANGELOG.md @launchdarkly/team-app-platform-product
+CHANGELOG.md @launchdarkly/team-automation