Documentation added for width and height

Summary: Width and height documentation

Reviewed By: emilsjolander

Differential Revision: D6978015

fbshipit-source-id: f62972acaf70be2b6df5056b5deed2a893c10b4c

website/contents/properties/width-height.md

@@ -6,7 +6,30 @@ hasPlayground: true
 
 ## Width and Height
 
+The `width` property in flexbox specifies the width of the element's content area. Similarly `height` property specifies the height of the element's content area.
 
+Both `width` and `height` can take following values
+
+### Auto
+It is the default Value, Yoga calculates the width/height for the element
+ 
+### Pixels
+Defines the width/height in px
+
+### Percentage
+Defines the width or height in percentage of its parents width or height respectively
+
+Lets start to play with playground. For starter, lets try fiddling with `width`:
+
+1. Click on the root view and set `width = auto`, you would see that it would shrink to fit its children. 
+2. Lets try giving pixel value. Click on any child view, and change its width(say 300), you would now see child view's width is updated
+3. Say you want to make your child view half of root view's width. Type 50% in your view's width field, and voila, your view is 50% of its parent.
+
+You can do similar things with `height` too. Keep fiddling 😉
+
+### Width
 <controls prop="width"></controls>
 
+### Height
 <controls prop="height"></controls>
+