Make developing more attractive

Nobody has claimed this yet.

This is a meta issue on making developing more attractive, in order to gain new developers and also to keep current developers.

You can reference other issues here, whether new or existing.
They *must not* be detailed, e.g. you can write "LMMS needs better VST support because the project will die without VST", but you can't reference issues like "VST abc fails in situation xyz".

This thread is using sub-captions to categorize the issues. Of course, those can be changed by request.

## How to make the work itself (coding/versioning) more attractive

* [ ] Guide for setting up QtCreator (#4934)
* [x] Make master branch spit out nightly builds, treat master as the preferred version for power users and developers. (#3347)
* [x] Master branch is unstable (#4931)
* [ ] Pay more attention to PRs (#4935)
* [ ] How to get the code better documented? (#4932)
* [x] Extend [plugin development wiki page](https://github.com/LMMS/lmms/wiki/Plugin-development) @JohannesLorenz . Should be up-to-date and cover Native, Lv2, maybe SPA.
* [ ] Improve [plugin development wiki page](https://github.com/LMMS/lmms/wiki/Plugin-development) to explain basics like `NotePlayHandle`s, see @DeRobyJ 's post below.

## Sources of new developers

* [ ] Google Summer of Code 2020?
* [x] Hacktoberfest 2019?
* [ ] Social Media?

## Keep LMMS competitive with other DAWs

If a project is fun to program, but no one uses it, it's still not attractive to devs.

* [ ] Make LMMS realtime safe

This is a broad meta issue tracking ways to make LMMS development more attractive. Start by reviewing the linked sub-issues, especially #4934, #4935, and #4932, along with the plugin development wiki page. The checklist and its categories indicate the scope, but no single implementation or completion boundary is defined.

Written by the indexing model from the issue text.