Add missing } to token example (actions#153)

Author: squalrus

packages/github/README.md

@@ -12,7 +12,7 @@ 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 }
+// myToken: ${{ secrets.GITHUB_TOKEN }}
 // https://help.github.com/en/articles/virtual-environments-for-github-actions#github_token-secret
 const myToken = core.getInput('myToken');