workaround for MRK057

Author: sarahhaggarty

docs/topics/compiler-plugins/custom-compiler-plugins.md

@@ -15,10 +15,11 @@ API is **unstable**. You need to invest significant ongoing effort to maintain i
 
 ### The Kotlin compiler and compiler plugins
 
+<p></p> <!-- workaround for MRK057: Paragraph can only contain inline elements-->
 <list columns="2">
     <li>
         <p></p>
-        <br>
+        <br/>
         <img src="compiler-stages.svg" width="400" alt="Kotlin compilation stages"/>
     </li>
     <li>