Merged ddtools-types fork into master

[zacharylove]

• Moved spell interfaces and definitions into spell.ts
• Moved shared utilities and references into util.ts
• Updated links to point to new spells and utilities' locations
• Added more attributes to spells
• Added descriptive comments to spells and utilities

[Apexal]

Great changes and documentation. However, it looks like the indentation isn't consistent across files. Can you make sure it's 2 spaces and each file is formatted? I just use VSCode's formatting tool for this.