Add clarification on remove framing terms
Add clarification on remove framing terms

I had a question about what to do if the framing was bad just like
the example I added to the documentation. I was concerned that
there might be a way that Nerves.UART handles protocol errors,
but it does not. I thought some documentation might help others
reach the idea sooner.

Amos King @adkron <amos@binarynoggin.com>
nerves-project/nerves_uart