It just means that file won't support extra features, like ignoring commented lines. It
will still analyze that file.
Take a look at the settings menu for more customization and fine-tuning. If you hover over
the label, a tooltip will provide you with additional info of what it does.
Selecting a directory may cause your browser to ask if you trust my website. Relax, I'm not
stealing your info.
The rest is pretty self-explanatory.
If you are still having other issues, please post it on the GitHub
repository and I will try to fix it. Be sure to look at the console (Ctrl-Shift-J on
Chrome) for any errors.