Merge on-screen keyboard (#211)

There is little to say about the on-screen keyboard, so I've merged it into the keyboard section of a bad page.

Author: Frosty-J

_includes/wiki_index.md

@@ -89,7 +89,6 @@
   * [Gesture detection](/wiki/input/gesture-detection)
   * [Gyroscope](/wiki/input/gyroscope)
   * [Mouse, Touch and Keyboard](/wiki/input/mouse-touch-and-keyboard)
-  * [On screen keyboard](/wiki/input/on-screen-keyboard)
   * [Polling](/wiki/input/polling)
   * [Simple text input](/wiki/input/simple-text-input)
   * [Vibrator](/wiki/input/vibrator)

_includes/wiki_sidebar.md

@@ -128,7 +128,6 @@
   * [Gesture detection](/wiki/input/gesture-detection)
   * [Gyroscope](/wiki/input/gyroscope)
   * [Mouse, Touch and Keyboard](/wiki/input/mouse-touch-and-keyboard)
-  * [On screen keyboard](/wiki/input/on-screen-keyboard)
   * [Polling](/wiki/input/polling)
   * [Simple text input](/wiki/input/simple-text-input)
   * [Vibrator](/wiki/input/vibrator)

wiki/input/mouse-touch-and-keyboard.md

@@ -2,14 +2,17 @@
 title: Mouse, Touch and Keyboard
 redirect_from:
   - /wiki/mouse,-touch-&-keyboard
+  - /wiki/input/on-screen-keyboard
 ---
 The main input devices libGDX supports are the mouse on the desktop/browser, touch screens on Android and keyboards. Let's review how libGDX abstracts those.
 
 ## Keyboard
-Keyboards signal user input by generating events for pressing and releasing a key. Each event carries with it a key-code that identifies the key that was pressed/released. These key-codes differ from platform to platform. libGDX tries to hide this fact by providing its own key-code table, see the [Keys](https://javadoc.io/doc/com.badlogicgames.gdx/gdx/latest/com/badlogic/gdx/Input.Keys.html) [(source)](https://github.com/libgdx/libgdx/blob/master/gdx/src/com/badlogic/gdx/Input.java#L63) class. You can query which keys are currently being pressed via [Polling](/wiki/input/polling).
+Keyboards signal user input by generating events for pressing and releasing a key. Each event carries with it a key-code that identifies the key that was pressed/released. These key-codes differ from platform to platform. libGDX tries to hide this fact by providing its own key-code table, see the [Keys](https://javadoc.io/doc/com.badlogicgames.gdx/gdx/latest/com/badlogic/gdx/Input.Keys.html) [(source)](https://github.com/libgdx/libgdx/blob/master/gdx/src/com/badlogic/gdx/Input.java#L69) class. You can query which keys are currently being pressed via [Polling](/wiki/input/polling).
 
 Key-codes alone do not give us information about which character the user actually entered. This information is often derived from the state of multiple keys, e.g. the character 'A' is generated by the keys 'a' and 'shift' being pressed simultaneously. In general, deriving characters from the keyboard's state (which keys are down) is non-trivial. Thankfully, the operating system usually has a means to hook up an event listener that not only reports key-code events (key pressed/key released), but also characters. libGDX uses this mechanism under the hood to provide you with character information. See [Event Handling](/wiki/input/event-handling).
 
+As most Android and iOS devices lack a physical keyboard, we can use `Gdx.input.setOnscreenKeyboardVisible(true)` to bring up the on-screen keyboard. It is also possible to specify which type of keyboard to display by passing in an [`OnscreenKeyboardType`](https://javadoc.io/doc/com.badlogicgames.gdx/gdx/latest/com/badlogic/gdx/Input.OnscreenKeyboardType.html).
+
 ## Mouse & Touch
 Mouse and touch input allow the user to point at things on the screen. Both input mechanisms report the location of interaction as 2D coordinates relative to the upper left corner of the screen, with the positive x-axis pointing to the right and the y-axis pointing downward.