Add an initial planned feature list for `gemini`

Dependencies

• [2] L6GZJGTU Add READMEs

Change contents

• replacement in gemini/README.md at line 4
  [2.112]→[2.112:188](∅→∅)
  − that interact with the [Gemini protocol](https://gemini.circumlunar.space/).
  [2.112]
  + that interact with the [Gemini protocol](https://gemini.circumlunar.space/).

  +

  + ## planned fetaures

  +

  + * feature-gated parsers using `nom`

  + * a `gemtext` module for representing `text/gemini` content