Make it easier to locallly build and release a new version

[m00qek]

This PR introduces a Makefile that makes it really easy to build this patch locally. Please read this for more information.

It also adds two GithubActions: one that runs on every commit and another on that runs on tags. The former creates a .bps patch on every change and the latter automatically generates a release page whenever a tag in the format v* is pushed. This makes it easy to test proposed changes and also to do releases.

In order to enable this automation the maintainer must upload its game dump/backup to a closed, personal, Dropbox account. More details on the releasing guide.

It was necessary to change the format and location of the config files .bso in order to generate the releases automatically.

Oh, all commands used by the Makefile are executed in a Docker image that contains flips and asar.

You can see it working in this PR and in this release.

Fixes #34