Add interfaces for redux actions and starte

Author: alexandr-g

src/features/counter/types.ts

@@ -0,0 +1,15 @@
+import { INCREMENT_COUNTER, DECREMENT_COUNTER } from './actionTypes'
+
+interface IncrementCounterAction {
+  type: typeof INCREMENT_COUNTER
+}
+interface DecrementCounterAction {
+  type: typeof DECREMENT_COUNTER
+}
+export type CounterActionTypes = IncrementCounterAction | DecrementCounterAction
+
+export interface SystemState {
+  count: {
+    value: number
+  }
+}