Resolved the hyperlink color and <h1> A11y bugs

Author: Satwik Kumar Sharma

source/nodejs/adaptivecards-site/themes/adaptivecards/layout/index.ejs

@@ -31,7 +31,7 @@
 
 	<div class="w3-center" style="max-width: 600px; margin: auto">
 		<div class="w3-margin w3-padding-32">
-			<h1 class="w3-xxlarge"><%- site.data.home.en.heading %></h1>
+			<h2 class="w3-xxlarge"><%- site.data.home.en.heading %></h2>
 			<div class="accent-paragraph"><%- site.data.home.en.heading_paragraph %></div>
 			<div class="w3-padding-16">
 				<button role="link" onclick="window.location.href='https://docs.microsoft.com/en-us/adaptive-cards/'"

source/nodejs/adaptivecards-site/themes/adaptivecards/source/css/style.css

@@ -30,7 +30,7 @@ body > #headerAreaHolder {
 
 .ac-blue {
   color: #fff !important;
-  background-color: #0050c5 !important;
+  background-color: var(--blue) !important;
 }
 
 .breadcrumbs {
@@ -646,19 +646,19 @@ button .fa-check {
 
 .ac-blue {
   color: #fff !important;
-  background-color: #0b78d0 !important;
+  background-color: var(--blue) !important;
 }
 
 .homepage a:link,
 .homepage a:visited {
-  color: #0b78d0;
+  color: var(--blue);
   font-size: 15px;
   line-height: 29px;
   font-weight: 600;
 }
 
 .homepage a:hover {
-  color: blue;
+  color: var(--blue-light);
 }
 
 .schema-content a:link,