parse .md docs into data structure

[maxim-uvarov]

it would be cool to interact with .md documents - parse them into data structure, reliably update and save back as .md documents.

[maxim-uvarov]

One application:

open README.md | numd parse | group-by h1 | items {|k v| let index = $k | parse '# {number} - {name}' | get number.0; let content = $v.content | to text; $content | save --force $'content/($index).md'