updated README

Author: sommersoft

README.rst

@@ -14,26 +14,22 @@ Adafruit CircuitPython module for the LIS3DH accelerometer.
 
 Note this module is made to work with CircuitPython and not MicroPython APIs.
 
+Usage Example
+=============
+
 See the guide at: https://learn.adafruit.com/circuitpython-hardware-lis3dh-accelerometer
 
 Dependencies
 =============
 This driver depends on:
 
 * `Adafruit CircuitPython <https://github.com/adafruit/circuitpython>`_
+* `Bus Device <https://github.com/adafruit/Adafruit_CircuitPython_BusDevice>`_
 
 Please ensure all dependencies are available on the CircuitPython filesystem.
 This is easily achieved by downloading
 `the Adafruit library and driver bundle <https://github.com/adafruit/Adafruit_CircuitPython_Bundle>`_.
 
-API Reference
-=============
-
-.. toctree::
-   :maxdepth: 2
-
-   api
-
 Contributing
 ============
 
@@ -64,3 +60,26 @@ Then run the build:
 .. code-block::shell
 
     circuitpython-build-bundles --filename_prefix adafruit-circuitpython-lis3dh --library_location .
+
+Sphinx documentation
+-----------------------
+
+Sphinx is used to build the documentation based on rST files and comments in the code. First,
+install dependencies (feel free to reuse the virtual environment from above):
+
+.. code-block:: shell
+
+    python3 -m venv .env
+    source .env/bin/activate
+    pip install Sphinx sphinx-rtd-theme
+
+Now, once you have the virtual environment activated:
+
+.. code-block:: shell
+
+    cd docs
+    sphinx-build -E -W -b html . _build/html
+
+This will output the documentation to ``docs/_build/html``. Open the index.html in your browser to
+view them. It will also (due to -W) error out on any warning like Travis will. This is a good way to
+locally verify it will pass.