feat: show custom keybindings in the help menu

[joelazar]

This adds the feature of showing the custom keybindings in the help menu. When the custom keybinding is extended with a name key, it will render that, otherwise it will use the command itself.

Example:

    - key: g
      command: >
        cd {{.RepoPath}} && lazygit
      name: lazygit

[dlvhdr]

Thank you! I've always wanted this :)

From some quick testing I see a few issues:

• Keys in the universal section don't show up - this is an existing missing feature, but would be great to add that together with this PR
• For some reason, in the C key case below, I'm not seeing the name in the help menu

So I would check against this config:

keybindings:
  universal:
    - key: g
      name: lazygit
      command: >
        cd {{.RepoPath}} && lazygit
  prs:
    - key: O
      builtin: checkout
    - key: C
      name: review in octo
      command: >
        tmux new-window -c {{.RepoPath}} '
        nvim -c ":silent Octo pr edit {{.PrNumber}}"
        '

[joelazar]

Thank you! I've always wanted this :)

From some quick testing I see a few issues:

* Keys in the `universal` section don't show up - this is an existing missing feature, but would be great to add that together with this PR

* For some reason, in the C key case below, I'm not seeing the `name` in the help menu

So I would check against this config:

keybindings:
  universal:
    - key: g
      name: lazygit
      command: >
        cd {{.RepoPath}} && lazygit
  prs:
    - key: O
      builtin: checkout
    - key: C
      name: review in octo
      command: >
        tmux new-window -c {{.RepoPath}} '
        nvim -c ":silent Octo pr edit {{.PrNumber}}"
        '

Perfect, thanks for the feedback. I'll look into them and sort them out in the next 1–2 days 🙏