Use better docs theme and clarify docs

documentation/source/conf.py

@@ -1,7 +1,7 @@
 author = 'decentral1se'
 copyright = '2019, decentral1se'
 html_static_path = ['_static']
-html_theme = 'alabaster'
+html_theme = 'sphinx_rtd_theme'
 master_doc = 'index'
 project = 'flat-tree'
 templates_path = ['_templates']

documentation/source/index.rst

@@ -1,12 +1,13 @@
 .. include:: ../../README.rst
    :end-before: _documentation
 
-Table of Contents
-*****************
-
 .. toctree::
+   :maxdepth: 1
+   :hidden:
 
    install
+   upgrade
+   example
    modules-api
    other-impls
    contribute

documentation/source/upgrade.rst

@@ -0,0 +1,7 @@
+*******
+Upgrade
+*******
+
+.. code-block:: bash
+
+    $ pip install --upgrade flat-tree