Update README to include deployment on RPi

[darraghbr]

I attempted to build and run the software on a Pi and encountered a couple of issues.

Running the chromedriverinstall.sh script comes up with

"E: Package 'google-chrome-stable' has no installation candidate"

as of course we only get chromium on the Pi.

Entering the venv and running the runtests.sh script I get

"ModuleNotFoundError: No module named 'RPi'"

When I then run docker build I get

"Error response from daemon: dockerfile parse error line 1: unknown instruction: E{�<�>U�(�"

I will try to build and run using docker desktop and see if I get anything further.

[fpdotmonkey]

"ModuleNotFoundError: No module named 'RPi'"

I'm guessing this is an issue with adafruit blinka. We'll need to investigate further

https://github.com/adafruit/Adafruit_Blinka