Shrink heading anchor links to 1em, fixes links in headings

In readonly mode, the heading anchor links spanned the whole width so
far, overlaying potential links in headings.

Fixes: #3822

Signed-off-by: Jonas <jonas@freesources.org>

src/nodes/Heading/HeadingView.vue

@@ -90,6 +90,8 @@ div.ProseMirror {
 	h1,h2,h3,h4,h5,h6 {
 		position: relative;
 		.heading-anchor[contenteditable="false"] {
+			// Shrink clickable area of anchor permalinks to not overlay the heading
+			width: 1em;
 			opacity: 0;
 			padding: 0;
 			left: -1em;
@@ -110,14 +112,5 @@ div.ProseMirror {
 			outline: none;
 		}
 	}
-
-	// Shrink clickable area of anchor permalinks while editing
-	&[contenteditable="true"] {
-		h1,h2,h3,h4,h5,h6 {
-			.heading-anchor {
-				width: 1em;
-			}
-		}
-	}
 }
 </style>