Updated intro and alphabetized Layers doc

docs/api/core/Layers.html

@@ -11,8 +11,15 @@
 		<h1>[name]</h1>
 
 		<div class="desc">
-		An object providing a bit mask and accessor method used to control an [page:Object3D]'s visibility.
-		A [page:Layers] object assigns an [page:Object3D] to 0 or more of 32 layers numbered 0 to 31.
+		An object providing a [link:https://en.wikipedia.org/wiki/Mask_(computing) bit mask] and accessor methods
+		used to control an [page:Object3D]'s visibility.
+		A [page:Layers] object assigns an [page:Object3D] to 0 or more of 32 layers numbered 0 to 31.<br /><br />
+
+		This is used to control visibility - an object must share a layer with a [page:Camera camera]
+		to be visible when that camera's view is renderered.<br /><br />
+
+		All classes that inherit from [page:Object3D] have a [property:layers] property which is an instance
+		of this class.
 		</div>
 
 
@@ -34,44 +41,39 @@
 
 		<h2>Methods</h2>
 
-		<h3>[method:null set]( [page:Integer layer] )</h3>
-		<div>
-		layer - an integer from 0 to 31.
-		</div>
+		<h3>[method:null disable]( [page:Integer layer] )</h3>
 		<div>
-		Set the layer mask to the value *layer*.
+		layer - an integer from 0 to 31.<br /><br />
+
+		Remove *layer* from the mask.
 		</div>
 
 		<h3>[method:null enable]( [page:Integer layer] )</h3>
 		<div>
-		layer - an integer from 0 to 31.
-		</div>
-		<div>
+		layer - an integer from 0 to 31.<br /><br />
+
 		Add *layer* to the mask.
 		</div>
 
-		<h3>[method:null disable]( [page:Integer layer] )</h3>
-		<div>
-		layer - an integer from 0 to 31.
-		</div>
+		<h3>[method:null set]( [page:Integer layer] )</h3>
 		<div>
-		Remove *layer* from the mask.
-		</div>
+		layer - an integer from 0 to 31.<br /><br />
 
-		<h3>[method:null toggle]( [page:Integer layer] )</h3>
-		<div>
-		layer - an integer from 0 to 31.
-		</div>
-		<div>
-		Toggle the *layer* value in the mask.
+		Set the layer mask to the value *layer*.
 		</div>
 
 		<h3>[method:Boolean test]( [page:Integer layers] )</h3>
 		<div>
-		layers - a 32bit bit mask of layer numbers.
+		layers - a 32bit bit mask of layer numbers.<br /><br />
+
+		Returns true if *layers* and [page:.mask] have any bits set in common.
 		</div>
+
+		<h3>[method:null toggle]( [page:Integer layer] )</h3>
 		<div>
-		Returns true if *layers* and .mask have any bits set in common.
+		layer - an integer from 0 to 31.<br /><br />
+
+		Toggle the *layer* value in the mask.
 		</div>
 
 		<h2>Source</h2>