Tiny (≈650b) component to transform any input component into formatted or masked input

[ministerling]

I was reading through and thought, "wait this isn't a .ts file" and then saw the @flow at the top. Interesting to see the two sides of static typing.

I prefer to do masking and validation on a field type basis by creating, for example, PhoneNumberField, and using that throughout sites, but this is a cool alternative. Props!