add support for framed protocols #4
Description
I'd like to support framing to make it easy to parse protocols like KISS, HDLC, etc.
I don't know enough about these protocols yet to know how to best abstract this, but this PR is a start: #3
Before I merge that in, however I think I'll wait to see if I can get some thoughts / input from other folks about the kinds of framing they need for the projects they'd want to use bydantic for.