Chore/baseline gaps (#3)

* chore: add MIT LICENSE and self-hosting renovate.json

Licenses the shared Renovate preset permissively (MIT) and adopts the
org preset on this repo itself, so its own GitHub Actions stay updated.
Closes the baseline license/dependency-update gaps.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* add line to readme

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: CameronBrooks11

README.md

@@ -1 +1,3 @@
-# renovate-config
+# renovate-config
+
+Shared org configuration for Renovate, the automated dependency update tool.