Added documentation generating script (for separate github repo and discord), automatic updating of discord documentation channel

[BossFlea]

• Added documentation generating script
  • Highly customizable using separate config (custom table columns per category, etc.)
  • Recursively scans command directory
    • Looks for a .docmetadata.json file in every subdirectory, optionally containing a directory title, description and other options to include in the documentation
  • Full (github) and simplified (discord) modes to accommodate discord's restrictive formatting
    • Uses prettier's programmatic API for table formatting (if installed)
    • Simplified version generates just a list of commands (no tables), by default
  • Insert parts of the documentation tables into an existing README at specific markers (HTML comments)
    • Fetch current README or message template for discord from either an URL or a local file (configurable)
• Renamed one-time-scripts directory to just scripts, to serve as the general scripts directory
• Added the documentation script's default output files to .gitignore
• Updated and improved all command descriptions, as they're now included in the auto-generated README
• Added an auto-updating feature for the discord documentation channel
  • Triggered automatically on bot startup or manually using /updatedocs on discord (requires Admin permission or higher)
  • Only replaces the message if there are changes
  • Splits message if necessary
  • Added config options for channel ID, documentation file path and debug toggle for the feature