Add documentation

This makes it clear that people can call these methods.

docs/API.md

@@ -113,6 +113,10 @@ protocol stream.
   - The `capabilities` event is fired when `RFB.capabilities` is
     updated.
 
+[`pointerlock`](#pointerlock)
+  - The `pointerlock` event is fired when the Pointer Lock is acquired (or
+    released) by the canvas.
+
 ### Methods
 
 [`RFB.disconnect()`](#rfbdisconnect)
@@ -146,6 +150,9 @@ protocol stream.
 [`RFB.clipboardPasteFrom()`](#rfbclipboardPasteFrom)
   - Send clipboard contents to server.
 
+[`RFB.requestPointerLock()`](#rfbrequestPointerLock)
+  - Requests that the RFB canvas acquire a Pointer Lock.
+
 ### Details
 
 #### RFB()
@@ -262,6 +269,15 @@ The `capabilities` event is fired whenever an entry is added or removed
 from `RFB.capabilities`. The `detail` property is an `Object` with the
 property `capabilities` containing the new value of `RFB.capabilities`.
 
+#### pointerlock
+
+The `pointerlock` event is fired when the state of the canvas' Pointer Lock has
+changed, either because it has successfully acquired the lock and will have
+full control of the mouse pointer, or because the lock was released by the user
+pressing the ESC key or performing a browser-specific gesture. The `detail`
+property is an `Object` with the property `pointerlock` containing whether the
+lock is currently held or not.
+
 #### RFB.disconnect()
 
 The `RFB.disconnect()` method is used to disconnect from the currently
@@ -383,3 +399,19 @@ to the remote server.
 
 **`text`**
   - A `DOMString` specifying the clipboard data to send.
+
+#### RFB.requestPointerLock()
+
+The `RFB.requestPointerLock()` method is used to request that the RFB canvas
+hold a [Pointer
+Lock](https://developer.mozilla.org/en-US/docs/Web/API/Pointer_Lock_API), which
+hides the mouse cursor and provides relative motion events. This must be called
+directly from an event handler where a user has directly interacted with the
+browser for the browser to allow this.
+
+If the acquisition of the pointer lock is successful, a `pointerlock` event
+will be fired.
+
+##### Syntax
+
+    RFB.requestPointerLock( );