feat(store-devtools): add REDUX_DEVTOOLS_EXTENSION injection token to public API (#3338)

Author: edusperoni

modules/store-devtools/src/index.ts

@@ -1,6 +1,7 @@
 export { StoreDevtoolsModule } from './instrument';
 export { LiftedState, RECOMPUTE } from './reducer';
 export { StoreDevtools } from './devtools';
+export { REDUX_DEVTOOLS_EXTENSION } from './extension';
 export {
   StoreDevtoolsConfig,
   StoreDevtoolsOptions,