Choose type checker

[mwermelinger]

Since there are adaptors for 2 other type checkers, it seems a shame not to use them. Add a flag -t or --type to set the type checker to use? If no flag is given, should it mean to not check methods, or to use pyrefly, or to use whichever typechecker is installed? What if multiple are?

[densnow]

The thought did cross my mind about this. As you say it is a shame not to use them. If #88 goes ahead, it might be best to use pyrefly implicitly, when no flag is given.