init submodules

Author: Nicolas Béreux

.github/workflows/docs.yaml

@@ -15,7 +15,7 @@ jobs:
           python-version: 3.12
       - name: init submodule
         run:
-	  git submodule update --init --recursive
+          git submodule update --init --recursive
       - name: Install dependencies
         run: |
           pip install sphinx sphinx_rtd_theme myst_parser sphinxcontrib-bibtex sphinx-gallery matplotlib