[aprssig] Information organization

[Scott Howard]

Hi Everyone,

I started trying to synthesize the specification related content from
aprs.org into a more structured format. Following Hessu's example, I
made the following github repo to organize the notes. The goal is not
to revise or change anything, just to make an inventory, collect
thoughts, and begin structuring what already exists. The hope is to
both give some clarity for newcomers as well as organize info for
whatever comes next. It's a bit work-in-progress, so it's very open to
suggestions, corrections, additions, and edits.

The document is here:
https://github.com/KD9PDP/aprs-notes/blob/main/protocol.md

You can make comments to specific lines here:
https://github.com/KD9PDP/aprs-notes/pull/1/commits/b52e576ca444b2ee100cb1c6d4bd6291ff197280

There's a bunch that can be done, so if anyone has any interest in
tackling anything, please go ahead and build on it. You can file an
"issue" to let others know what you're working on so people don't
duplicate effort.

-Scott