Fixed docs pipeline

.gitlab-ci-docs.yml

@@ -10,6 +10,7 @@ docs:
     #  -- we won't see any future improvements of the mkdocs and mkdocs-material packages
     - pip install mkdocs
     - pip install mkdocs-material
+    - pip install mkdocs-minify-plugin
 
     # This is my own extension that we use to insert the $VERSION env variable into the documentation
     - pip install pymdown-env