Clean up "*.search" API method documentation pages

Summary:
Ref T9964. Building tables in Remarkup is kind of neat-ish but ends up feeling kind of hacky, and requires weird workarounds if any of the values have | in them.

Switch to normal elements instead.

Also move the magic "ids" and "phids" to be more like real fields. I'll clean this up fully in a diff or two, it's just a little tricky because Maniphest has an "ids" field.

Test Plan: {F1024294}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9964

Differential Revision: https://secure.phabricator.com/D14768