fix doc how to release

Author: Jannis-Mittenzwei

doc/user_guide/how_to_release.rst

@@ -1,12 +1,12 @@
 How to Release?
 ===============
 
-#.  Use :code:`nox -s release:prepare` to prepare the project for a new release.
+#.  Use :code:`TAG=<name>` to set a variable named **"TAG"**
+#.  Use :code:`nox -s release:prepare -- ${TAG}` to prepare the project for a new release.
 #.  Merge your **Pull Request** to the **default branch**
 #.  Use :code:`git remote show origin | sed -n '/HEAD branch/s/.*: //p'` to output the **default branch**
 #.  Use :code:`git checkout <default branch>` Switch to the **default branch**
 #.  Use :code:`git pull` to update branch
-#.  Use :code:`TAG=<name>` to set a variable named **"TAG"**
 #.  Use :code:`git tag "${TAG}"` to create a new tag in your repo
 #.  Use :code:`git push origin "${TAG}"` to push it to remote
 #.  GitHub workflow **CD** reacts on this tag and starts the release process