Update README

Dependencies

• [2] N3U3GWEL Fix README formatting
• [3] JS6JZ7IA Add an initial planned feature list for `gemini`
• [4] WJROXZ3C Add note to README thanking mgattozzi
• [*] L6GZJGTU Add READMEs

Change contents

• replacement in gemini/README.md at line 9
  [2.64]→[2.64:90](∅→∅)
  − - [ ] parsers using `nom`
  [2.64]

  [2.90]
  + - [X] parsers using `nom`
• edit in gemini/README.md at line 14
  [3.45]

  [3.45]
  + i also need to set up CI/CD... not sure the best way to approach this with

  + pijul hosting.
• edit in gemini/README.md at line 17
  [3.46]

  [3.46]
  +