docs: Sidebar structure

Author: tony

docs/index.md

@@ -1,3 +1,7 @@
+---
+hide-toc: true
+---
+
 (index)=
 
 ```{include} ../README.md
@@ -6,6 +10,8 @@
 
 ## Table of Contents
 
+:hidden:
+
 ```{toctree}
 :maxdepth: 2
 
@@ -18,8 +24,15 @@ sessions
 windows
 panes
 api
-glossary
+
+```
+
+```{toctree}
+:caption: Project
+:hidden:
+
 developing
 history
-
+glossary
+GitHub <https://github.com/tmux-python/libtmux>
 ```