docs: Remove references to wrapped reducer function

Changing reducers to be directly exported.

Issue: #3192

Author: AleenaSA

projects/ngrx.io/content/guide/entity/adapter.md

@@ -70,11 +70,7 @@ export const initialState: State = adapter.getInitialState({
   selectedUserId: null,
 });
 
-const userReducer = createReducer(initialState);
-
-export function reducer(state: State | undefined, action: Action) {
-  return userReducer(state, action);
-}
+export const userReducer = createReducer(initialState);
 </code-example>
 
 ## Adapter Collection Methods
@@ -149,7 +145,7 @@ export const initialState: State = adapter.getInitialState({
   selectedUserId: null,
 });
 
-const userReducer = createReducer(
+export const userReducer = createReducer(
   initialState,
   on(UserActions.addUser, (state, { user }) => {
     return adapter.addOne(user, state)
@@ -198,9 +194,6 @@ const userReducer = createReducer(
   })
 );
 
-export function reducer(state: State | undefined, action: Action) {
-  return userReducer(state, action);
-}
 
 export const getSelectedUserId = (state: State) => state.selectedUserId;
 

projects/ngrx.io/content/guide/store/reducers.md

@@ -69,17 +69,14 @@ The initial values for the `home` and `away` properties of the state are 0.
 The reducer function's responsibility is to handle the state transitions in an immutable way. Create a reducer function that handles the actions for managing the state of the scoreboard using the `createReducer` function.
 
 <code-example header="scoreboard.reducer.ts">
-const scoreboardReducer = createReducer(
+export const scoreboardReducer = createReducer(
   initialState,
   on(ScoreboardPageActions.homeScore, state => ({ ...state, home: state.home + 1 })),
   on(ScoreboardPageActions.awayScore, state => ({ ...state, away: state.away + 1 })),
   on(ScoreboardPageActions.resetScore, state => ({ home: 0, away: 0 })),
   on(ScoreboardPageActions.setScores, (state, { game }) => ({ home: game.home, away: game.away }))
 );
 
-export function reducer(state: State | undefined, action: Action) {
-  return scoreboardReducer(state, action);
-}
 </code-example>
 
 <div class="alert is-important">