Update readme to show how to use the secret GITHUB_TOKEN (#131)

* Update readme to show how to use the secret GITHUB_TOKEN

* Adds in link to docs - which I feel seem to be scattered in repos & official docs

packages/github/README.md

@@ -11,6 +11,9 @@ const github = require('@actions/github');
 const core = require('@actions/core');
 
 // This should be a token with access to your repository scoped in as a secret.
+// The YML workflow will need to set myToken with the GitHub Secret Token
+// myToken: ${{ secrets.GITHUB_TOKEN }
+// https://help.github.com/en/articles/virtual-environments-for-github-actions#github_token-secret
 const myToken = core.getInput('myToken');
 
 const octokit = new github.GitHub(myToken);