Notes on permissions for github token

base/codebuild_artifact/README.md

@@ -19,4 +19,10 @@ The service account (mdr-aws-codebuild) needs to have a personal access token ma
 1) In github, go to `settings->Developer Settings->Personal Access Tokens`
 2) Click 'Generate Token'
 3) Give it a name (e.g. `terragrunt`)
-4) TBD.. which permissions are needed?
+4) Give it the following permission groups:
+  * repo
+  * admin:repo_hook
+5) Create the token.
+
+Record it someplace safe.
+