Try adding plantuml

bin/mdshow

@@ -97,7 +97,7 @@ $(MDSHOW_CONFIG)/reveal.js:
 	mv $@/reveal.js-4.1.0/.??* $@/reveal.js-4.1.0/* $@
 	rmdir $@/reveal.js-4.1.0
 	cd $@ && \
-		npm install && npm add node-jq decktape gulp
+		npm install && npm add node-jq decktape gulp reveal-plantuml
 	# workarounds for the new reveal-js release
 	cd $@/dist && \
 		ln -s ../plugin .

default.revealjs

@@ -85,6 +85,7 @@ $body$
   <script src="$revealjs-url$/plugin/search/search.js"></script>
   <script src="$revealjs-url$/plugin/notes/notes.js"></script>
   <script src="$revealjs-url$/plugin/highlight/highlight.js"></script>
+  <script src="$revealjs-url$/node_modules/reveal-plantuml/dist/reveal-plantuml.min.js"></script>
 
   <script>
 
@@ -290,7 +291,7 @@ $if(mathjax)$
 $endif$
 
         // Optional reveal.js plugins
-        plugins: [ RevealHighlight, RevealZoom, RevealNotes, RevealSearch, RevealMath ]
+        plugins: [ RevealHighlight, RevealZoom, RevealNotes, RevealSearch, RevealMath, RevealPlantUML ]
       });
     </script>
   $for(include-after)$