add pages for uploading and help

pdb-js/src/app/app.module.ts

@@ -3,10 +3,18 @@ import { NgModule } from '@angular/core';
 
 import { AppRoutingModule } from './app-routing.module';
 import { AppComponent } from './app.component';
+import { MainPageComponent } from './main-page/main-page.component';
+import { HelpPageComponent } from './help-page/help-page.component';
+import { UploadPageComponent } from './upload-page/upload-page.component';
+//import { VisualizationPageComponent } from './visualization-page/visualization-page.component';
 
 @NgModule({
   declarations: [
-    AppComponent
+    AppComponent,
+    MainPageComponent,
+    HelpPageComponent,
+    UploadPageComponent,
+    //VisualizationPageComponent,
   ],
   imports: [
     BrowserModule,