Following PR #21306 which added the new generic plugin-platform hooks,
update the three platform-authoring docs so plugin authors find them:
- website/docs/developer-guide/adding-platform-adapters.md: expand the
'What the Plugin System Handles Automatically' table with env-only
auto-enable + cron delivery + hermes-config UI entries rows. Add
three new sections — 'Env-Driven Auto-Configuration', 'Cron
Delivery', 'Surfacing Env Vars in hermes config' — covering the
hook signatures, plugin.yaml rich-dict format, and the
home_channel-key special case. Update the main register() example
to pass env_enablement_fn + cron_deliver_env_var inline so readers
see them on their first pass. Upgrade the PLUGIN.yaml snippet to
show bare-string + rich-dict + optional_env.
- website/docs/guides/build-a-hermes-plugin.md: the thin platform
example in the build-a-plugin tour now includes env_enablement_fn
and cron_deliver_env_var, plus an optional_env block in the inline
plugin.yaml. Keeps pointing to the developer-guide page for the
full treatment.
- gateway/platforms/ADDING_A_PLATFORM.md: the in-repo reference
shallow-points at the docsite but now names the three new hooks
explicitly so contributors reading the source tree know what
they're for. Also adds teams + google_chat as reference
implementations alongside irc.
5c08b851df