Merge pull request #2340 from lgasp/patch-1

Add a milestone to docs

docs/gantt.md

@@ -61,6 +61,7 @@ gantt
     Future task in critical line        :crit, 5d
     Create tests for renderer           :2d
     Add to mermaid                      :1d
+    functionality added                 :milestone
 
     section Documentation
     Describe gantt syntax               :active, a1, after des1, 3d
@@ -130,6 +131,11 @@ You can divide the chart into various sections, for example to separate differen
 To do so, start a line with the `section` keyword and give it a name. (Note that unlike with the [title for the entire chart](#title), this name is *required*.
 
 
+### Milestones
+
+You can add milestones to the diagrams. Milestones differ from tasks as they represent a signle instant in time and are identifiedd by the keyword `milestone`
+
+
 ## Setting dates
 
 `dateFormat` defines the format of the date **input** of your gantt elements. How these dates are represented in the rendered chart **output** are defined by `axisFormat`.