Originally from @SNvMK in microsoft/vscode#120734

So, in python 3.10, there is match/case syntax. Currently, it is just white words(for monokai). I'd like if you add highlight for this. Thanks

a = 'world'
match a:
    case 'world':
        print('Hello!')
    case _:
        print('I dont know you!')

Currently the match and case are only tokenized as source.python.