Basic style for markdown-generated Table of Contents

This styles a Table of Content (ToC) generated by the markdown toc extension:
https://python-markdown.github.io/extensions/toc/

docs/toc.md

@@ -0,0 +1,33 @@
+# Table of contents documentation
+
+## Markdown
+
+Markdown has a [toc extension](https://python-markdown.github.io/extensions/toc/) that can be enabled and used directly.
+Once enabled just add `[TOC]` in the markdown document where you want the table of contents to appear.
+
+Configure the `toc` extension through `MARKDOWN` setting in `pelicanconf.py`:
+
+``` python
+MARKDOWN = {
+    "extension_configs": {
+        "markdown.extensions.toc": {
+            "title": "Table of Contents"
+        },
+    },
+}
+```
+
+Refer to [Markdown's toc extension documentation](https://python-markdown.github.io/extensions/toc/) for full settings.
+
+If you use the [i18n_subsites plugin](https://github.com/getpelican/pelican-plugins/tree/master/i18n_subsites) you can override the table of contents" title:
+
+``` python
+import copy
+
+I18N_SUBSITES = {
+    "es": {
+        "MARKDOWN": copy.deepcopy(MARKDOWN),  # copy to override later
+    }
+}
+I18N_SUBSITES["es"]["MARKDOWN"]["extension_configs"]["markdown.extensions.toc"]["title"] = "Índice de contenidos"
+```