First Angular Application to prototype few variants

1. https://v4.angular.io/guide/quickstart
   Till Step 3, your dev environment will be setup. Few observations:
   • SYSTEM Environment variables are set for node and npm
   • USER Environment variables are set for ng (angular cli)
   • Can be checked through command 'where ng'
2. Explaining the flow:
   • index.html is the first page of our web-application
   • The tag <app-root> triggers the app component to kick in. It will get replaced with the app.component.html and its model is in app.component.ts
   • The linking is working through the use of decorator (to mark it as Angular component) in app.component.ts which has selector as "app-root"
   • And this is what makes it as single page application
3. More changes done as per https://angular.io/tutorial/toh-pt1:
   • Adding <app-heroes> won't work if added in index.html as it's not a bootstrap module which has been referenced through main.ts [TODO: confirm this] Even adding it to list of bootstrap in app.module.ts didn't help
   • Two way binding can be validated by modifying the text in input field
4. Learnt about *ngFor, *ngIf, @Input, CSS classes during runtime
5. Created a child component of the original Heroes component
6. Introduced angular services in the app
   • So far, the need of introducing service seems to be decoupling the data source (backend calls) and pure front-end i.e. deal with the data
   • Services can be injected for testing and the same components can be re-used
7. Routing in Angular app
   • Export the RouterModule doesn't need import as well. Though it may not work but, it's because of different reason.
   • In import, calling RouterModule.forRoot imports the module and calls the function at the same time.
   • Adding Routing.forRoot in the constructor of routing module doesn't work. [TODO: Explore it]
   • Passing parameters through the routing and navigation done