updated README

Author: sommersoft

README.rst

@@ -10,6 +10,10 @@ Introduction
     :target: https://discord.gg/nBQh6qu
     :alt: Discord
 
+.. image:: https://travis-ci.org/adafruit/Adafruit_CircuitPython_AVRprog.svg?branch=master
+    :target: https://travis-ci.org/adafruit/Adafruit_CircuitPython_AVRprog
+    :alt: Build Status
+
 Program your favorite AVR chips directly from CircuitPython with this handy helper class that will let you make stand-alone programmers right from your REPL. Should work with any/all AVR chips, via SPI programming. Tested with ATmega328, ATtiny85 and ATmega2560
 
 Dependencies
@@ -27,14 +31,6 @@ Usage Example
 
 See examples folder for full examples that progam various bootloaders onto chips.
 
-API Reference
-=============
-
-.. toctree::
-   :maxdepth: 2
-
-   api
-
 Contributing
 ============
 
@@ -65,3 +61,26 @@ Then run the build:
 .. code-block:: shell
 
     circuitpython-build-bundles --filename_prefix adafruit-circuitpython-avrprog --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.