Parsing improvements

[reeseovine]

Last steps before merging:

• [ ] Review the code and simplify/debug things as needed
• [ ] Update autocomplete
• [ ] Update demo
• [ ] Update documentation
• [ ] Add/update Typescript type definition file

[reeseovine]

What should autocomplete look like now?

• Start suggesting on first character after separator to reduce clutter and opinionation.
• If part of a shorthand combination, gather suggestions that can be found with only 1 form.
• Don't add "or" to suggestions; it's unnecessary.