Update docs with newly-added rego functions

[evankanderson]

Summary

We added several new Rego functions, but didn't put them in the documentation.

(There are some other cases of this as well, for example, we don't have a doc with the ingest types.)

Long-term, we should figure out how to auto-generate these, but for now, I've manually updated them.

Change Type

Mark the type of change your PR introduces:

• Bug fix (resolves an issue without affecting existing features)
• Feature (adds new functionality without breaking changes)
• Breaking change (may impact existing functionalities or require documentation updates)
• Documentation (updates or additions to documentation)
• Refactoring or test improvements (no bug fixes or new functionality)

Testing

N/A, though I've used almost all of these functions.

Review Checklist:

• Reviewed my own code for quality and clarity.
• Added comments to complex or tricky code sections.
• Updated any affected documentation.
• Included tests that validate the fix or feature.
• Checked that related changes are merged.

[JAORMX]

Thanks a lot for adding these!