Create a release script

Our release process is non-standard and undocumented. Let's automate it. This MR will create a script that builds front-end assets, cuts a tag, and provides instructions for manual steps needed to complete a release.

The script works like this:

$ ./scripts/release.sh -h
Usage: ./scripts/release.sh [-h | --help] [-H | --head <branch>] [--dry-run] [-f | --force] <tag_name>
  -h, --help            Show this help message and exit.
  -H, --head <branch>   (Optional) The branch to return to after release. Defaults to current branch.
  --dry-run             Print the operations that would be performed, but do not execute them.
  -f, --force           Ignore precondition checks (for testing/debugging only).
  <tag_name>            The name of the release tag to create.

Attached → is an example of output it produces.