Fix jsdocs

[jamesobrooks]

Purpose

When we have JSDocs, it is most helpful if they properly follow the syntax.

Major Changes

• Move types to their proper place in @param tags.
• Add @return tags where needed.
• Add @template tags where generics are used.
• Add stronger typing to api2.ts interface and functions as the JSDoc actually caused build failures without these changes.

Testing/Validation

Ran build successfully.