docs: document optional ca_cert server verification
docs: reflect review fixes (archive default, helper error semantics, TLS warning)
docs: clarify IN/OUT group direction semantics IN and OUT are from the group's point of view: IN = user may send into the group, OUT = user receives its traffic. Adds an explainer to the User Account Management page, rewrites the vague direction param descriptions and fixes the reversed readers/writers examples.
Initial wiki docs: Home, Getting Started, Home API, Mission API, User Account Management API