add support for the chalkboard plugin
diff --git a/README.Rmd b/README.Rmd
index e36cebd..219dd65 100644
--- a/README.Rmd
+++ b/README.Rmd
@@ -308,6 +308,7 @@
 | [notes](https://github.com/hakimel/reveal.js/#speaker-notes) | Present per-slide notes in a separate browser window. |
 | [zoom](http://lab.hakim.se/zoom-js/) | Zoom in and out of selected content with Alt+Click. |
 | [search](https://github.com/hakimel/reveal.js/blob/master/plugin/search/search.js) | Find a text string anywhere in the slides and show the next occurrence to the user. |
+| [chalkboard](https://github.com/rajgoel/reveal.js-plugins/tree/master/chalkboard) | Include handwritten notes within a presentation. |
 
 Note that the use of plugins requires that the `self_contained` option be set to false. For example, this presentation includes both the "notes" and "search" plugins:
 
@@ -319,6 +320,21 @@
         reveal_plugins: ["notes", "search"]
     ---
 
+You can specify additional options for the `chalkboard` plugin using `reveal_options`, for example:
+
+    ---
+    title: "Habits"
+    output:
+      revealjs::revealjs_presentation:
+        self_contained: false
+        reveal_plugins: ["chalkboard"]
+        reveal_options:
+          chalkboard:
+            theme: whiteboard
+            toggleNotesButton: false
+    ---
+
+
 ## Advanced Customization
 
 ### Includes