Add text for dev tooling

Author: woojiahao

docs/tooling/developer-tooling.md

@@ -0,0 +1,15 @@
+---
+title: Developer tooling
+nav_order: 3
+parent: Tooling
+---
+
+## Publishing new versions of libraries
+
+When working on `app` or the other supported libraries, if you attach one of the following labels:
+
+- `bump:major`
+- `bump:minor`
+- `bump:patch`
+
+The CI will automatically tag the merge commit when the pull request is merged and automatically perform a publish for the library/tool.