adds pdf preview support for html formatter

src/auto_archiver/formatters/templates/html_template.html

@@ -286,11 +286,11 @@
         // logic for enabled/disabled greyscale
         // Get references to the checkboxes and images/videos
         const safeImageViewCheckbox = document.getElementById('safe-media-view');
-        const imagesVideos = document.querySelectorAll('img, video');
+        const visualPreviews = document.querySelectorAll('img, video,embed');
 
         // Function to toggle grayscale effect
         function toggleGrayscale() {
-            imagesVideos.forEach(element => {
+            visualPreviews.forEach(element => {
                 if (safeImageViewCheckbox.checked) {
                     // Enable grayscale effect
                     element.style.filter = 'grayscale(1)';
@@ -307,7 +307,7 @@
         safeImageViewCheckbox.addEventListener('change', toggleGrayscale);
 
         // Handle the hover effect using JavaScript
-        imagesVideos.forEach(element => {
+        visualPreviews.forEach(element => {
             element.addEventListener('mouseenter', () => {
                 // Disable grayscale effect on hover
                 element.style.filter = 'none';

src/auto_archiver/formatters/templates/macros.html

@@ -32,6 +32,10 @@ No URL available for {{ m.key }}.
         Your browser does not support the video element.
     </video>
 </div>
+{% elif 'application/pdf' in m.mimetype %}
+<div>
+    <embed src="{{ url }}" width="100%" height="400px"/>
+</div>
 {% elif 'audio' in m.mimetype %}
 <div>
     <audio controls>