Add community-cc-list.md file

This adds the initial cc list file.

Fixes 227

Author: jrfnl

.github/community-cc-list.md

@@ -0,0 +1,14 @@
+<!--
+PHP_CodeSniffer Community CC List
+
+This list will be used on select tickets to ping the wider PHP_CodeSniffer community for input.
+
+If you want to be on this list, feel free to submit a PR to add yourself.
+If you want to be removed from the list, dito, submit a PR to remove yourself and it will be merged without questions.
+
+PRs adding/removing other people to/from the list will only be merged if the people being added/removed leave a comment on the PR consenting to it.
+
+For more context, see https://github.com/PHPCSStandards/PHP_CodeSniffer/issues/227
+-->
+
+/cc @...