For v3.x

[attakei]

Overview

Main goal is to drop design for old environments.

Targets

• Drop old python versions
  • [x] System-level drop Python 3.6 and olders.
• Drop old Sphinx versions
  • [x] System-level drop Sphinx 3.x and olders.
  • [ ] Strong warning Sphinx 4.x
  • [ ] Warning Sphinx 5.x
• Drop already marked deprecated
  • [ ] revealjs_script_conf is dict only
  • [x] Change default static file directory
  • [x] Remove font configuration and directive options

Other tasks

• [ ] Write migration guide