notes.md: explain possible_case_numbers?number= (#194)
notes.md: explain possible_case_numbers?number= (#194)

* Update notes.md

Explain `number` parameter to `possible_case_numbers.pl` per unminified js comments.

* notes.md: Hidden APIs -> APIs; +mobile_query.pl

The "Hidden APIs" was really a single not-hidden API. Retitle as APIs.

Also add the mobile_query.pl API.

* pacer/notes.md: fixup typo (browser)

freelawproject/juriscraper,freelawproject/juriscraper