Start parsing hrules
Added myself to the readme

Since I'm contributing now...
Created function appendElementMarker()

Does exactly the same thing as before, but avoids duplicated code throughout
the parser.
Start parsing image spans
Start parsing autolinks
Started parsing list flags

This will allow us to distinguish between ordered/unordered lists
Merge pull request #162 from trello/bypass-parser

Added more parsing rules to the base Bypass parser