Accessibility add alt to images

layouts/shortcodes/blocks/cover.html

@@ -25,7 +25,7 @@
 {{ end }}
 <section id="{{ $blockID }}" class="row td-cover-block td-cover-block--height-{{ $height }} js-td-cover td-overlay td-overlay--dark -bg-{{ $col_id }}">
   <div class="container td-overlay__inner">
-    <img id="banner-hero-logo" class="hero-logo" src="images/tekton-horizontal-color.png">
+    <img id="banner-hero-logo" class="hero-logo" alt="tekton logotype" src="images/tekton-horizontal-color.png">
     <div class="row">
       <div class="col-6">
         <div class="text-left">

layouts/shortcodes/blocks/manifesto.html

@@ -7,7 +7,7 @@
 	<div class="container" style="max-width: 600px;">
 		<div class="row">
 			<div class="col mb-5 text-center">
-				<a href="https://cd.foundation/"><img src="/partner-logos/cdf.png" class="img-fluid"></a>
+				<a href="https://cd.foundation/"><img src="/partner-logos/cdf.png" alt="cd.foundation" class="img-fluid"></a>
 			</div>
 		</div>
 	</div>

layouts/shortcodes/blocks/partners-alternate.html

@@ -5,7 +5,7 @@
     <div class="container" style="max-width: 600px;">
 		<div class="row">
 			<div class="col mb-5 text-center">
-				<a href="https://github.com/tektoncd/friends"><img src="/partner-logos/tekton-friends.png" class="img-fluid"></a>
+				<a href="https://github.com/tektoncd/friends"><img src="/partner-logos/tekton-friends.png" alt="tekton friends" class="img-fluid"></a>
 			</div>
 		</div>
     </div>