Refacter explanatory comments

base/github_actions_s3_bucket/iam.github-actions.tf

@@ -1,13 +1,6 @@
-# the 'splunk-addon-for-aws' role is created in all accounts via
-# the base/account_standards module.
 #
-# Then, there is an instance profile (for use in the partition holding moose)
-# and a user account (for use in the partion _not_ holding moose) that
-# with keys for moose.
+# Create an IAM user (and group) to use with GitHub Actions
 #
-# That instance profile/user is allowed to assumerole into the
-# 'splunk-addon-for-aws' role in the other accounts.
-
 ######################
 # Access keys
 #