diff --git a/README.md b/README.md
index f300a19..a3d5f39 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ npm install geojson2h3
 
 ## Example Usage
 
-```
+```javascript
 import geojson2h3 from 'geojson2h3';
 
 const polygon = {
@@ -57,11 +57,13 @@ const feature = geojson2h3.h3SetToFeature(hexagons);
 <a name="module_geojson2h3.featureToH3Set"></a>
 
 ### geojson2h3.featureToH3Set(feature, resolution) ⇒ <code>Array.&lt;String&gt;</code>
-Convert a GeoJSON feature to a set of hexagons. Only hexagons whose centers
-fall within the feature will be included. Note that conversion from GeoJSON
+Convert a GeoJSON feature to a set of hexagons. *Only hexagons whose centers
+fall within the feature will be included.* Note that conversion from GeoJSON
 is lossy; the resulting hexagon set only approximately describes the original
 shape, at a level of precision determined by the hexagon resolution.
 
+![featureToH3Set](./doc-files/featureToH3Set.png)
+
 **Kind**: static method of [<code>geojson2h3</code>](#module_geojson2h3)  
 **Returns**: <code>Array.&lt;String&gt;</code> - H3 indexes  
 
diff --git a/doc-files/README.md.tmpl b/doc-files/README.md.tmpl
index 4f94d47..f89fb8b 100644
--- a/doc-files/README.md.tmpl
+++ b/doc-files/README.md.tmpl
@@ -15,7 +15,7 @@ npm install geojson2h3
 
 ## Example Usage
 
-```
+```javascript
 import geojson2h3 from 'geojson2h3';
 
 const polygon = {
diff --git a/doc-files/featureToH3Set.png b/doc-files/featureToH3Set.png
new file mode 100644
index 0000000..239cf35
Binary files /dev/null and b/doc-files/featureToH3Set.png differ
diff --git a/src/geojson2h3.js b/src/geojson2h3.js
index 05ac86b..6dc61a1 100644
--- a/src/geojson2h3.js
+++ b/src/geojson2h3.js
@@ -69,10 +69,12 @@ function featureCollectionToH3Set(featureCollection, resolution) {
 // Public API functions
 
 /**
- * Convert a GeoJSON feature to a set of hexagons. Only hexagons whose centers
- * fall within the feature will be included. Note that conversion from GeoJSON
+ * Convert a GeoJSON feature to a set of hexagons. *Only hexagons whose centers
+ * fall within the feature will be included.* Note that conversion from GeoJSON
  * is lossy; the resulting hexagon set only approximately describes the original
  * shape, at a level of precision determined by the hexagon resolution.
+ *
+ * ![featureToH3Set](./doc-files/featureToH3Set.png)
  * @static
  * @param  {Object} feature     Input GeoJSON: type must be either `Feature` or
  *                              `FeatureCollection`, and geometry type must be