adds getToken(string,string) and deleteToken(string,string) to typings

lib/index.d.ts

@@ -1088,6 +1088,8 @@ declare module 'react-native-firebase' {
       interface InstanceId {
         delete(): Promise<void>;
         get(): Promise<string>;
+        getToken(authorizedEntity: string, scope: string): Promise<string>;
+        deleteToken(authorizedEntity: string, scope: string): Promise<void>;
       }
     }