Example names do not match repo name

[kattni]

The examples all start with rgbdisplay_ and should begin with rgb_display_. Examples need to be renamed to match CircuitPython library standards.

The lines including this file name in the docs/examples.rst file must also be updated to reflect the name change, e.g.:

.. literalinclude:: ../examples/current_file_name.py
    :caption: examples/current_file_name.py
    :linenos:

would be updated to:

.. literalinclude:: ../examples/current_file_name_changed.py
    :caption: examples/current_file_name_changed.py
    :linenos:

[makermelissa]

Fixed by #31