refactor(community.service): add shareReplay(1) to avoid multiple requests

Author: NyaGarcia

src/app/shared/services/community.service.ts

@@ -2,7 +2,7 @@ import { Communities } from '@shared/interfaces';
 import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
 import { Observable } from 'rxjs';
-import { map } from 'rxjs/operators';
+import { map, shareReplay } from 'rxjs/operators';
 
 @Injectable({
   providedIn: 'root',
@@ -13,9 +13,10 @@ export class CommunityService {
   constructor(private httpClient: HttpClient) {}
 
   get communities(): Observable<Communities> {
-    return this.httpClient
-      .get<Communities>(this.JSON_COMMUNITIES)
-      .pipe(map(communities => this.normalizeCommunities(communities)));
+    return this.httpClient.get<Communities>(this.JSON_COMMUNITIES).pipe(
+      map(communities => this.normalizeCommunities(communities)),
+      shareReplay(1),
+    );
   }
 
   private normalizeCommunities(communities: Communities): Communities {