Update and Clean up release workflow

[akrigline]

• Removes old gulp files that aren't necessary anymore
• Removes package.json(s) since we no longer have any dependencies
• Removes unecessary workflow files
• Sets the 'master' manifest's download to always get the latest repo archive (Since we modify the release manifest in the workflow this is fine)
• Replaces workflow with one similar to the League Template:
  1. Runs when a new release or pre-release is created on GH
  2. Modifies the module.json going out to properly link to this release's files and version number
  3. Zips up the modified module.json and all files in the repo
  4. Attaches the Zip and manifest to the created (pre-)release.

The manifest location doesn't change with these changes, so the update chain will not be broken, only the download is different.