Add Railiance canary chart template

tools/README_tools.md

@@ -66,6 +66,7 @@ This model emphasizes:
 ### `create_railiance_overlay_repo.sh`
 - Scaffolds a local Railiance overlay repo for a third-party upstream app.
 - Records upstream identity without vendoring upstream code.
-- Generates `railiance/app.toml`, a thin chart, stage values, tests, and runbooks.
+- Generates `railiance/app.toml`, a stage-aware canary chart, stage values,
+  tests, and runbooks.
 
 ✦ Railiance is not just code — it’s a way of letting infrastructure **colonize new worlds**.