DOC: Mention index.ipynb as alternative to index.rst

Author: mgeier

doc/usage.ipynb

@@ -40,8 +40,19 @@
     "\n",
     "For an example, see this project's  [conf.py](conf.py) file.\n",
     "\n",
-    "Once your `conf.py` is in place, edit the file named `index.rst` and add the file names of your notebooks (without the `.ipynb` extension) to the [toctree](https://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html#directive-toctree) directive.\n",
-    "For an example, see this project's `doc/index.rst` file."
+    "Once your `conf.py` is in place,\n",
+    "edit the file named `index.rst` and add the file names of your notebooks\n",
+    "(without the `.ipynb` extension)\n",
+    "to the\n",
+    "[toctree](https://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html#directive-toctree)\n",
+    "directive.\n",
+    "For an example, see this project's `doc/index.rst` file.\n",
+    "\n",
+    "Alternatively, you can delete the file `index.rst`\n",
+    "and replace it with your own notebook called `index.ipynb`\n",
+    "which will serve as main page.\n",
+    "In this case you can create the main [toctree](subdir/toctree.ipynb)\n",
+    "in `index.ipynb`."
    ]
   },
   {