Add type definition

src/utils/type.ts

@@ -0,0 +1,3 @@
+// https://github.com/Microsoft/TypeScript/issues/12215
+export type Diff<T extends string, U extends string> = ({ [P in T]: P } & { [P in U]: never } & { [x: string]: never })[T];
+export type Omit<T, K extends keyof T> = { [P in Diff<keyof T, K>]: T[P] };