Make the gix-renderer module a separate library

[Zulko]

Motivation:

Gix-Renderer does not depend on Vue and could therefore be its own library, which would allow the following:

• Other projects, built with any platform will be able to generate GIXes
• The GIF editor repo would really just focus on GIF editing
• Better, separate version management of the renderer and the editor.
• The gix-renderer repo would be a good place to write GIF generaiton tests and avoid feature regressions.

Note:

• Not urgent until there is a precise use case for it.
• We should probably move Gix to an organization of its own when this happens, to keep all repos at the same place.

Specs:

• gix-renderer is in its own repo.
• There is a Github pipeline for bumping versions and releasing.
• There is an easy recipe to develop the renderer and the editor at the same time.