Add `/suggest` command with subcommands for different kinds of suggestions

[Ernest314]

• tags
• emojis/stickers
• meme channel names
• commands
• farm routes
• resources
• other

Have different arguments for different subcommands (e.g. allow uploading a mockup of an emoji as an attachment argument). Always have the option for suggestions to be anonymous (or a subcommand is onlyanonymous)!

[Ernest314]

(all subcommands additionally have the optional [anonymous] argument)

• [ ] command
  • modal
    • description
• [ ] event
  • modal
    • description
• [ ] tag
  • modal
    • [name]
    • content
• [ ] farm-route
  • [file]
  • modal
    • material
    • description
• [ ] farm-material
  • material
• [ ] resource-cap
  • resource
• [ ] emoji
  • [file]
  • [description]
• [ ] meme-channel
  • name
• [ ] other
  • modal
    • description

[Ernest314]

Helptext could be something like

`/suggest <type> <options> [anonymous]` submits a suggestion.
    Emojis need a description, a file/mockup, or both.
    (We cannot follow up on anonymous suggestions.)