Format mapped type

[saschanaz]

Fixes #12960

Input:

type t  < T  > =   {
   [   P   in   keyof    T  ]   :   T  [  P  ]  
};

Current:

type t  < T  > = {
[P   in   keyof    T]: T[p]
};

Fixed:

type t<T> = {
    [P in keyof T]: T[P]
};

[mhegazy]

Thanks!