docs v3

[Licini]

Part of #1214

This involves 2 new major releases of doc-related workflows:

Most of works are done at compas-actions.docsversions:
compas-dev/compas-actions.docversions@v2.2.0...v3.0.0

This one is responsible to look at the gh-pages branch, find out all version folders. Sort them, remove older patches and pre-releases, and finally, generate the versions.json for the doc version drops-down list.
As the shell script approach is becoming too crazy deal with all sorts of version matching and comparing, I'm now switching this to Javascript action so things can be handled more programmatically.

When executed in Github actions, it will print out something like this, so we will have a good idea of what's going on:

All versions:  [
  '1.0.0',
  '1.9.0',
  '1.10.0',
  '1.12.5',
  '1.12.6',
  '2.0.0-alpha.1',
  '2.0.0-beta.2'
]
Formal release versions:  [ '1.0.0', '1.9.0', '1.10.0', '1.12.5', '1.12.6' ]
Stable version:  1.12.6
Version map:  {
  '1.0': [ '1.0.0' ],
  '1.9': [ '1.9.0' ],
  '1.10': [ '1.10.0' ],
  '1.12': [ '1.12.5', '1.12.6' ],
  '2.0': [ '2.0.0-alpha.1', '2.0.0-beta.2' ]
}
To delete:  [ '1.12.5', '2.0.0-alpha.1' ]
Deleted:  1.12.5
Deleted:  2.0.0-alpha.1
Versions JSON:  [
  {
    name: 'Latest',
    version: 'latest',
    url: 'https://compas.dev/compas/latest/'
  },
  {
    name: '2.0.0-beta.2',
    version: '2.0.0-beta.2',
    url: 'https://compas.dev/compas/2.0.0-beta.2/'
  },
  {
    name: '1.12.6 (stable)',
    version: '1.12.6',
    url: 'https://compas.dev/compas/1.12.6/'
  },
  {
    name: '1.10.0',
    version: '1.10.0',
    url: 'https://compas.dev/compas/1.10.0/'
  },
  { name: '1.9.0', version: '1.9.0', url: 'https://compas.dev/compas/1.9.0/' },
  { name: '1.0.0', version: '1.0.0', url: 'https://compas.dev/compas/1.0.0/' }
]

There is also some clean-up and happened at:
compas-dev/compas-actions.docs@v2.3.0...v3.0.0

[Licini]

@tomvanmele Any chance to look at this one? It will be nice we have this merged before beta