Support the match statement

[felix-hilden]

I haven't ever tried it (the feature, or how it works with autolink), but I suspect that it doesn't. So let's support it!

[felix-hilden]

The first obvious step is just parsing it in general, which already works. But I bet we could do something smart with it:

import lib

match _:
    case lib.Thing(attr=x):
        x  # lib.Thing().attr
    case lib.Thing(things=[lib.Another(attr=x), y])
        x, y  # x: lib.Another().attr, y: no link