lint: run w3c validator

index.html

@@ -102,7 +102,7 @@ <h1>yt player</h1>
     </div>
 
     <div id="expand-box" class="hidden" aria-label="click to reopen video" data-balloon-pos="left">
-      <img id="thumbnail" alt="video thumbnail"/>
+      <img id="thumbnail" src="" alt="video thumbnail"/>
       <div id="expand-hint-text">minimized video</div>
     </div>
 
@@ -123,14 +123,14 @@ <h1>yt player</h1>
           >close</span
         >
         <h3>help</h3>
-        <p>
+        <div>
           yt player is a simple video player for youtube videos
           <br>
-          made with &lt3 by
+          made with &lt;3 by
           <a href="https://www.github.com/unrealapex" target="_blank">unrealapex</a>
           <br>
           <p>click the arrows below to reveal help about that specific topic</p>
-        </p>
+        </div>
         <details>
           <summary>basic usage</summary>
           <p>
@@ -180,5 +180,6 @@ <h3>help</h3>
             and is lisenced under the <a href="https://github.com/unrealapex/yt-player/blob/main/LICENSE" target="_blank">apache 2.0 lisence</a>.
           </p>
       </div>
+    </div>
   </body>
 </html>