Change dump file name format, Marked 2 support

* Changed outfile format name to use strftime('%Y-%m-%d %H.%M.%S')
instead of isoformat() for naming to ensure the resulting file name can
be stored in Windows (or can sync via Dropbox)
* Add “commented” option to have the resulting file open in Marked 2
* Change a comment about the intent of the script
Merge pull request #3 from jjarava/master

Improvement to output file naming, Marked 2 optional support, comment clean up