Add echart module.

frontend/src/app/app.module.ts

@@ -3,6 +3,7 @@ import { NgModule } from '@angular/core';
 import { HttpClientModule, HTTP_INTERCEPTORS } from '@angular/common/http';
 import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
 import { InfiniteScrollModule } from 'ngx-infinite-scroll';
+import { NgxEchartsModule } from 'ngx-echarts';
 
 import { AppRoutingModule } from './app-routing.module';
 import { AppComponent } from './components/app/app.component';
@@ -106,6 +107,9 @@ import { SponsorComponent } from './components/sponsor/sponsor.component';
     NgbTypeaheadModule,
     FontAwesomeModule,
     SharedModule,
+    NgxEchartsModule.forRoot({
+      echarts: () => import('echarts')
+    })
   ],
   providers: [
     ElectrsApiService,