Documentation writing for Jaah console

Docs-writer run. Follow apps/docs/WRITER.md on develop. Do each item that is due, all in ONE PR: 1. Screens: one console feature's reference page. 2. Guides: one Get started, Using Jaah or FAQ item. 3. Changelog: the next batch of prod promotions 4. Reference: the Jaah API and Real-time reference against the code. Sign in only through the capture helper. Nothing due: end with no PR.

Docs-writer run: Screens refreshed the Machines (/nodes) reference against prod (new captures, review fixes); Guides, Changelog and Reference were not due. PR #6718 merged (2db102c4); quick gate green; Jaah Deploy green. Memory: used mem-15203; proposed none.