Feat: 카테고리 filter 관련 Reducer 생성 (#15)

src/redux/slices/filter.js

@@ -0,0 +1,22 @@
+import { createSlice } from '@reduxjs/toolkit';
+
+const initialState = {
+  category: '',
+};
+
+const slice = createSlice({
+  name: 'filter',
+  initialState,
+  reducers: {
+    setFilter: (state, action) => {
+      state.category = action.payload;
+    },
+    clearFilter: (state) => {
+      state.category = '';
+    },
+  },
+});
+
+// Reducer
+export const { setFilter, clearFilter } = slice.actions;
+export default slice.reducer;