Release of 2.3.0

[KodeStar]

It's been a long time since any updates, but here is the current state.

The plan was to rewrite Heimdall to be completely JS based, unofficially dubbed heimdalljs, however, the people helping with that project lost interest. Therefore, the revised plan is to update Heimdall's underlying framework to a version that will work on PHP 7.2.5 - 8.0 and continue development on this main version, then when this is released I will start integrating some of the new functionality from heimdalljs into Heimdall.

The updates to the underlying framework has been done, and some niggling issues have been resolved so if anyone wants to help with checking that 2.3.0 is ready for release, please pull the master version or use the :development docker tag.