diff --git a/README.md b/README.md
index 06be666..4224d3b 100644
--- a/README.md
+++ b/README.md
@@ -83,7 +83,8 @@ Sets overrides for the default attributes for the expected data structure of an
     category: undefined,
     entries: undefined,
     timestamp: 'timestamp',
-    text: 'text'
+    text: 'text',
+    url: 'url'
   };
 ```
 
diff --git a/example/milestones.html b/example/milestones.html
index 469db4e..b3a219a 100644
--- a/example/milestones.html
+++ b/example/milestones.html
@@ -50,8 +50,8 @@ <h1>Version Milestones</h1>
         <td><label for="select-orientation">Orientation</label></td>
         <td>
           <select id="select-orientation">
-            <option value="horizontal">Horizontal</option>
-            <option value="vertical" selected>Vertical</option>
+            <option value="horizontal" selected>Horizontal</option>
+            <option value="vertical">Vertical</option>
           </select>
         </td>
       </tr>
@@ -61,37 +61,31 @@ <h1>Version Milestones</h1>
   <script src="../build/d3-milestones.js"></script>
   <script>
     var data = [
-      { "timestamp" : "2012-09-09T00:00", "detail":"v1.0.0" },
-      { "timestamp" : "2012-09-10T00:00", "detail":"v1.0.1" },
-      { "timestamp" : "2012-09-12T00:00", "detail":"v1.1.0" },
-      { "timestamp" : "2012-09-15T00:00", "detail":"v1.1.1" },
-      { "timestamp" : "2012-09-26T00:00", "detail":"v1.2.0" },
-      { "timestamp" : "2012-10-10T00:00", "detail":"v2.0.0" },
-      { "timestamp" : "2012-10-31T00:00", "detail":"v2.1.0" },
-      { "timestamp" : "2012-11-07T00:00", "detail":"v2.2.0" },
-      { "timestamp" : "2012-11-25T00:00", "detail":"v2.2.1" },
-      { "timestamp" : "2012-12-01T00:00", "detail":"v2.3.0" },
-      { "timestamp" : "2012-12-05T00:00", "detail":"v2.3.1" },
-      { "timestamp" : "2013-01-03T00:00", "detail":"v3.0.0" },
-      { "timestamp" : "2013-01-09T00:00", "detail":"v3.0.1" },
-      { "timestamp" : "2013-01-16T00:00", "detail":"v3.1.0" },
-      { "timestamp" : "2013-01-16T00:00", "detail":"v4.0.0" },
-      { "timestamp" : "2013-01-17T00:00", "detail":"v4.0.1" },
-      { "timestamp" : "2013-02-08T00:00", "detail":"v4.1.0" },
-      { "timestamp" : "2013-03-06T00:00", "detail":"v4.1.1" },
-      { "timestamp" : "2013-03-06T00:00", "detail":"v4.2.0" },
-      { "timestamp" : "2013-03-09T00:00", "detail":"v4.3.0" },
-      { "timestamp" : "2013-03-27T00:00", "detail":"v4.4.0" },
-      { "timestamp" : "2013-04-13T00:00", "detail":"v4.5.0" },
-      { "timestamp" : "2013-05-04T00:00", "detail":"v5.0.0" },
-      { "timestamp" : "2013-07-06T00:00", "detail":"v5.0.1" },
-      { "timestamp" : "2013-08-01T00:00", "detail":"v5.1.0" }
+      { "timestamp": "2017-08-22T00:00", "detail": "v1.0.0-alpha1", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha1" },
+      { "timestamp": "2017-08-24T00:00", "detail": "v1.0.0-alpha2", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha2" },
+      { "timestamp": "2017-08-24T00:00", "detail": "v1.0.0-alpha3", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha3" },
+      { "timestamp": "2017-09-27T00:00", "detail": "v1.0.0-alpha4", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha4" },
+      { "timestamp": "2017-09-28T00:00", "detail": "v1.0.0-alpha5", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha5" },
+      { "timestamp": "2018-01-02T00:00", "detail": "v1.0.0-alpha6", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha6" },
+      { "timestamp": "2018-01-03T00:00", "detail": "v1.0.0-alpha7", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha7" },
+      { "timestamp": "2018-01-03T00:00", "detail": "v1.0.0-alpha8", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha8" },
+      { "timestamp": "2018-02-08T00:00", "detail": "v1.0.0-alpha9", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha9" },
+      { "timestamp": "2018-02-08T00:00", "detail": "v1.0.0-alpha10", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha10" },
+      { "timestamp": "2018-10-25T00:00", "detail": "v1.0.0-alpha11", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha11" },
+      { "timestamp": "2018-11-27T00:00", "detail": "v1.0.0-alpha12", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha12" },
+      { "timestamp": "2019-05-27T00:00", "detail": "v1.0.0-alpha13", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha13" },
+      { "timestamp": "2019-08-27T00:00", "detail": "v1.0.0-alpha14", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-alpha14" },
+      { "timestamp": "2020-05-29T00:00", "detail": "v1.0.0-beta1", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-beta1" },
+      { "timestamp": "2021-01-01T00:00", "detail": "v1.0.0-beta2", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0-beta2" },
+      { "timestamp": "2021-01-07T00:00", "detail": "v1.0.0", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.0" },
+      { "timestamp": "2021-01-18T00:00", "detail": "v1.0.1", "giturl": "https://github.com/walterra/d3-milestones/releases/tag/v1.0.1" },
     ];
 
     var timeline = milestones('#timeline')
       .mapping({
         timestamp: 'timestamp',
-        text: 'detail'
+        text: 'detail',
+        url: 'giturl'
       });
 
     var checkboxOptimize = document.getElementById('checkbox-optimize');