v0.2.0

New version and a brand new gnvim is here! Rewritten from the ground up
for gtk4, and now has:

• More complete and correct implementation of the ui api
• Custom rpc client
• Better code structure for easier development
• Updated UI
• Feature wise all the features are here.
• Rendering artefacts are now fixed, and the rendering performance should be
  better or at least on bar compared to the previous version.