fix: Modify PDF object tag for clearer intent

Summary of changes
- Updated the object tag for PDF rendering

Changes
- Added the part attribute to the object tag in viewer.mjs to specify that it is for PDF content, enhancing clarity and potential compatibility with modern web standards.

source/components/content/viewer.mjs

@@ -167,7 +167,7 @@ class Viewer extends CustomElement {
 		}
 
 		const html =
-			'<object data="' +
+			'<object part="pdf" data="' +
 			pdfURL +
 			'" width="100%" height="100%" type="application/pdf"></object>';