Update readme

README.md

@@ -93,3 +93,19 @@ obj="{{ job.kind }}"
 pcm_badge:
     base_classes: "base classes here"
 ```
+
+<br>
+
+# Development
+
+In the host project, require the bundle pinned to the `develop` branch:
+
+```bash
+composer require pcm/badge-bundle:dev-develop
+```
+
+The `dev-` prefix tells Composer to install from a branch rather than a tagged version. Each time you push a new commit to `develop`, run the following in the host project to pull it in:
+
+```bash
+composer update pcm/badge-bundle
+```