2.3.0

• Update packages:
  • mkdocs 1.2.3 -> 1.3.0 (fixes #29: jinja2 3.1.0 support)
  • mkdocs-material 8.0.2 -> 8.2.8
  • pygments 2.10.0 -> 2.11.2
  • mkdocs-markdownextradata-plugin 0.2.4 -> 0.2.5