Adding current editable file in comment

[ikenfin]

Hello! First of all, thank you for great plugin!
I need custom markdown preprocessing, so i've created a ruby script and connected it via cmd parameter. But, there is no options to send current editable filepath to this script (for example, i want generate base64 from images relative to editable filepath).
For my needs i've modified view_updated function for insert html comment string, containing filepath to markdown head.