docs(hermes): document GitHub and catalog installation

[loveRhythm1990]

What type of PR is this?

• docs (documentation)

Which issue(s) this PR fixes

No linked issue.

What this PR does / why we need it

The Hermes guide currently leads with a local directory copy and leaves Git installation as a future placeholder. Document three installation methods. The GitHub section provides a complete flow from obtaining an API key through installation, interactive configuration, readiness checks, and a cross-session memory example. The other methods use the shared setup instructions:

• GitHub installation pinned to the live-tested 3a5c5065b2820d56dd3d8ac8bb259a9424b1476e commit, with dependency preparation and activation flags.
• Installation by name through hermes plugins install memoria, explicitly conditional on acceptance of the Hermes catalog submission and availability in the user's catalog.
• The existing local-checkout method for development.

Use the interactive hermes memory setup wizard, select Memoria, and enter the API key with masked input. Document keeping or replacing an existing key and choosing opt-in capture. The tested CLI's hermes memory setup memoria only activates the provider and does not prompt for these settings. Include named-profile commands, update the stale unpublished-source wording, and link the guide from the main README's supported-agent badges.

Validation

• git diff --check passed.
• Checked that the pinned commit contains the plugin manifest, relative guide links resolve, and code fences are balanced.
• Confirmed install flags against the current Hermes CLI help. The fixed-SHA Git install was exercised in the October 9 live acceptance. Verified setup routing and schema prompts against the installed Hermes source; catalog-by-name installation remains unavailable until upstream accepts the entry.
• Documentation only; runtime code is unchanged.