Compatibility with python 3.8

[deathaxe]

The verbose argument of namedtuble function has been removed in python 3.7

The explicit use of it therefore causes the plugin to fail loading on ST's python 3.8 plugin host.

see: https://github.com/facelessuser/ExportHtml/blob/dad8ce2f9f0c8d5216cc2d6274ff468f36cb39ae/lib/color_scheme_matcher.py#L81

As it defaults to False it is safe to be removed from in favor of "forward" compatibility with ST4.

[facelessuser]

Yeah, it isn't even needed. I'm not quite sure why I thought it was.

[facelessuser]

I actually already have it removed locally as I was prepping the library to use the new coloraide version and cleaned up such things.

So this will be removed as I update mdpopups with the latest coloraide (ExportHtml just uses the vendored coloraide in mdpopups).