Fix check list~

* Change event to the pull_request event. Change idea~
instead of editing a message will edit the body of the~
PR using octokit update_pull_request method.~
* this will only run when the action on the PR is "opened".~
* will add the check list to the body of the PR.
Remove comment
Merge pull request #23 from amaabca/fix-pr-checklist

Fix check list~