Docs: cleanup api docs for parser utility

[am29d]

What were you searching in the docs?

Parser API docs are not up to date and there are missing types, functions and classes.

Is this related to an existing documentation section?

No response

How can we improve?

Add types, decorator, middleware, envelopes and schemas.

Got a suggestion in mind?

No response

Acknowledgment

• I understand the final update might be different from my proposed suggestion, or refused.