docs: add galaxy provider plugin docs

Author: Shaps

docs/third-party-plugins/commitizen-galaxy-provider.md

@@ -0,0 +1,24 @@
+
+# [commitizen-galaxy-provider](https://github.com/shaps/commitizen-galaxy-provider)
+
+A version provider to manage ansible collection versions. The provider updates the version in `galaxy.yml` so you can use commitizen to bump versions
+
+## Installation
+
+```sh
+pip install commitizen-galaxy-provider
+```
+
+## Usage
+
+Use `galaxy` as your `version_provider` in your config file
+
+Example of `.cz.yaml`
+
+```yaml
+---
+commitizen:
+  tag_format: $version
+  version_provider: galaxy
+  version_scheme: semver
+```