better use of Markdown formatting

- better line wrapping for code editing
- include links to referred doc files
- move non-usage info to the description section
- split code from text, in the usage section
- a couple other minor tweaks
minor grammar fix

So the first sentence in the description is actually a full sentence
Merge pull request #13 from waldir/patch-1

better use of Markdown formatting.
Thank you, I'll soon add addition description about the protocol.