doc: remove version in welcome page

Author: l-lin

demo/src/app/welcome.component.css

@@ -1,4 +1,4 @@
 .welcome-btn {
-  height: 180px;
+  height: 140px;
   padding: 10px;
 }

demo/src/app/welcome.component.html

@@ -24,24 +24,20 @@ <h1 class="header center-on-small-only">Angular DataTables</h1>
   <div class="row">
     <div class="col s12 m6 l6">
       <div class="center promo">
-        <a class="welcome-btn waves-effect btn" href="/angular-datatables/archives">
-          <span class="promo-caption">Using AngularJS</span>
-          <br />
-          <img src="assets/angularjs.png" />
+        <a class="welcome-btn waves-effect btn" routerLink="/getting-started">
+          <span class="promo-caption">Get started with Angular + DataTables</span>
           <br />
-          <span class="light center">angular-datatables {{ angularjsDataTablesVersion }}</span>
+          <img src="assets/angular.png" />
         </a>
       </div>
       <h4></h4>
     </div>
     <div class="col s12 m6 l6">
       <div class="center promo">
-        <a class="welcome-btn waves-effect btn" routerLink="/getting-started">
-          <span class="promo-caption">Using Angular</span>
-          <br />
-          <img src="assets/angular.png" />
+        <a class="welcome-btn waves-effect btn blue-grey lighten-1" href="/angular-datatables/archives">
+          <span class="promo-caption">Check old documentation (AngularJS)</span>
           <br />
-          <span class="light center">angular-datatables {{ angularDataTablesVersion }}</span>
+          <img src="assets/angularjs.png" />
         </a>
       </div>
       <h4></h4>

demo/src/app/welcome.component.ts

@@ -6,6 +6,4 @@ import { Component } from '@angular/core';
   styleUrls: ['./welcome.component.css']
 })
 export class WelcomeComponent {
-  angularjsDataTablesVersion = 'v0.Y.Z';
-  angularDataTablesVersion = 'v10.Y.Z';
 }