Fix links in README

README.rst

@@ -4,10 +4,12 @@ Ultimo
 Ultimo is an interface framework for micropython built around asynchronous
 iterators.
 
-- `Documentation <https://github.io/unital/ultimo>`_
-- `Tutorial <https://github.io/unital/ultimo/user_guide/tutorial.html>`_
-- `User Guide <https://github.io/unital/ultimo/user_guide.html>`_
-- `Examples <https://github.io/unital/ultimo/user_guide/examples.html>`_
+- `Documentation <https://unital.github.io/ultimo/>`_
+  - `User Guide <https://unital.github.io/ultimo/user_guide.html>`_
+    - `Installation <https://unital.github.io/ultimo/user_guide/installation.html>`_
+    - `Tutorial <https://unital.github.io/ultimo/user_guide/tutorial.html>`_
+    - `Examples <https://unital.github.io/ultimo/user_guide/examples.html>`_
+  - `API <https://unital.github.io/ultimo/api.html>`_
 
 Description
 -----------