Prevent Anchor icon appearing before the heading in Preview mode of comment box from getting cut off partially

What does this MR do and why?

This MR changes the margin-left property from -20px to -10px for all the anchor tags which appears inside heading when seen in Preview mode in comment box. The anchor icon now appear completely on the screen.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before

Before Changes

After changing margin-left to -10px

After_-10px

After changing margin-left to -15px

After_-15px

Related to #500958

app/assets/stylesheets/framework/markdown_area.scss

@@ -65,6 +65,14 @@
   min-height: 177px;
   padding: 10px 0;
   overflow-x: auto;
+
+  a.anchor {
+    margin-left: -1rem !important;
+  }
+
+  details a.anchor {
+    margin-left: -1.75rem !important;
+  }
 }
 
 .markdown-area {