17464 fix margins for custom-field markdown description (#17775)

* 17464 fix margins for custom-field markdown description

* 17464 fix margins for custom-field markdown description

* 17464 review changes

* 17464 update comments

netbox/project-static/styles/custom/_markdown.scss

@@ -28,16 +28,19 @@
 
 }
 
-// Remove the bottom margin of <p> elements inside a table cell
-td > .rendered-markdown {
-  max-height: 200px;
-  overflow-y: scroll;
-
+// Remove the bottom margin of the last <p> elements in markdown
+.rendered-markdown {
   p:last-of-type {
     margin-bottom: 0;
   }
 }
 
+// fix layout of rendered markdown inside a table cell
+td > .rendered-markdown {
+  max-height: 200px;
+  overflow-y: scroll;
+}
+
 // Markdown preview
 .markdown-widget {
   .preview {