Add alternate text to images

_includes/footer.html

@@ -5,7 +5,7 @@
     </span>
      • 
     <span>
-      Made with <img src="images/ablobcatheartsqueeze.webp" class="inline-image"> by <a href="https://fedi.absturztau.be/Craftplacer" target="_blank">Craftplacer</a>
+      Made with <img src="images/ablobcatheartsqueeze.webp" class="inline-image" alt="blobcat squeezing heart emoji"> by <a href="https://fedi.absturztau.be/Craftplacer" target="_blank">Craftplacer</a>
     </span>
   </span>
 </footer>

index.html

@@ -5,12 +5,12 @@ layout: default
 <div class="mdl-shadow--4dp landing-section">
   <div class="mdl-grid landing-content">
     <div class="mdl-cell mdl-cell--12-col mdl-cell--6-col-desktop mdl-cell--2-offset-desktop mdl-cell--middle">
-      <img class="app-icon" src="images/icon.webp">
+      <img class="app-icon" src="images/icon.webp" alt="Husky icon">
         <p class="landing-title">
           Husky
         </p>
         <p class="landing-subtitle">
-          a client for <img class="inline-image" src="images/fediverse.svg"> federated social networks
+          a client for <img class="inline-image" src="images/fediverse.svg" alt="Fediverse icon"> federated social networks
         </p>
       <div class="landing-downloads">
         <a href="{{ site.data.downloads.fdroid }}" class="mdl-button mdl-button--raised mdl-button--accent">
@@ -25,7 +25,7 @@ layout: default
       </div>
     </div>
     <div class="mdl-cell mdl-cell--3-col mdl-cell--middle mdl-cell--hide-phone mdl-cell--hide-tablet">
-      <img class="landing-image" src="images/screenshot.webp">
+      <img class="landing-image" src="images/screenshot.webp" alt="Screenshot of Husky">
     </div>
   </div>
   <div class="scroll-hint">