doc: densify releasing doc (#217)

Copier-coller !

docs/development/releasing.md

@@ -1,6 +1,10 @@
 # Release workflow
 
-1. Fill the `CHANGELOG.md` with the new version
+1. Fill the `CHANGELOG.md` with the new version. You can write it manually or use the auto-generated release notes by Github:
+    1. Go to [project's releases](https://github.com/geotribu/cli/releases) and click on `Draft a new release`
+    1. In `Choose a tag`, enter the new tag
+    1. Click on `Generate release notes`
+    1. Copy/paste the generated text from `## What's changed` until the line before `**Full changelog**:...` in the CHANGELOG.md replacing `What's changed` with the tag and the publication date
 1. Change the version number in `__about__.py`
 1. Apply a git tag with the relevant version: `git tag -a 0.3.0 {git commit hash} -m "New awesome feature"`
 1. Push tag to main branch: `git push origin --tags`