v0.1.0

First version!

The core functionality is on par with the `mailcap` library found in the
python stdlib. Mailcap files are parsed from the $MAILCAPS env or
default locations and can be queried from a collection with a mime type
as key.

This library was originally created to be a dependency for a soon-to-be
created custom opener (e.g. as a superset of XDG_OPENER), as mailcap
files are much more flexible and easier to configure than having to
create multiple `*.desktop` files. As such, despite all mailcap fields
being accounted for, it's not yet comprehensive in its original purpose
as a configuration for multimedia mail.