Add notes to internal docs

- contrib doc should mention 'make vendor-schemas' for vendoring
- add a releasing doc with the procedure written down

Author: sirosen

CONTRIBUTING.md

@@ -46,6 +46,11 @@ Hooks are defined in `src/check_jsonschema/catalog.py`, and rendered to
 
     make generate-hooks
 
+Schemas are pulled down based on this same config. If you want to update the
+vendored schema copies, run
+
+    make vendor-schemas
+
 ## Documentation
 
 All of the features of `check-jsonschema` should be documented in the readme

RELEASING.md

@@ -0,0 +1,5 @@
+# Releasing
+
+- Bump the version with `./scripts/bump-version.py NEW_VERSION`
+- Add, commit with `git commit -m 'Bump version for release'`, and push
+- Publish the release with `make release`