Add styling to rendered-markdown class to clamp height and add scrollbar (#17237)

* Add clamp_height to the markdown filter which limits max height to 200 (scrollable) on the container div

* Remove clamp_height option, apply scrolling style to all markdown divs inside td's

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

@@ -30,6 +30,9 @@
 
 // Remove the bottom margin of <p> elements inside a table cell
 td > .rendered-markdown {
+  max-height: 200px;
+  overflow-y: scroll;
+
   p:last-of-type {
     margin-bottom: 0;
   }