`ctrl+enter` should publish/update release #2696

When creating or editing a release, ctrl+enter (or cmd+enter) won't do anything.

Normally this shortcut is set to submit the form from textarea elements (like when creating a new issue, leaving a comment, leaving a review, etc) but it doesn't work when creating a release.

Example URL: https://github.com/sindresorhus/refined-github/releases/new