implement ota updates

docs/gitea-runner.md

@@ -92,7 +92,9 @@ docker compose logs -f           # expect: "runner registered successfully"
 ```
 
 That is it. The runner appears in Gitea under the scope you took the token from,
-with its labels listed beside it.
+with its labels listed beside it. For the release process that uses this runner —
+tags, secrets, artifacts, deployment and rollback — see
+[`production-builds.md`](production-builds.md).
 
 ### What the pieces do