Add game state boolean ref docs (#1694)

* Add game state boolean doc refs

* Add check for _img validity

* JS guru tricks

docs/reference/game.md

@@ -47,6 +47,9 @@ game.startCountdown(10000);
 game.gameOver();
 game.pause();
 game.resume();
+game.isGameOver()
+game.isRunning();
+game.isPaused();
 ```
 
 ## See also
@@ -57,4 +60,5 @@ game.resume();
 [add score](/reference/game/add-score), [score](/reference/game/score), [set score](/reference/game/set-score),
 [set life](/reference/game/set-life), [add life](/reference/game/add-life), [remove life](/reference/game/remove-life),
 [start countdown](/reference/game/start-countdown), [game over](/reference/game/game-over),
-[pause](/reference/game/pause), [resume](/reference/game/resume)
+[pause](/reference/game/pause), [resume](/reference/game/resume),
+[is game over](/reference/game/is-game-over,) [is running](/reference/game/is-running), [is paused](/reference/game/is-paused)

docs/reference/game/is-game-over.md

@@ -0,0 +1,25 @@
+# is Game Over
+
+Find out if the game is over or not.
+
+```sig
+game.isGameOver()
+```
+
+## Returns
+
+* a [boolean](/types/boolean) value that is `true` if the game is over or `false` if not.
+# Example
+
+Be kind and give the player some points for trying.
+
+```blocks
+if (game.isGameOver() && game.score() < 10) {
+    game.addScore(10 - game.score())
+}
+```
+
+## See also
+
+[is running](/reference/game/is-running),
+[is paused](/reference/game/is-paused)

docs/reference/game/is-paused.md

@@ -0,0 +1,28 @@
+# is Paused
+
+Find out if the game is paused or not.
+
+```sig
+game.isPaused()
+```
+
+## Returns
+
+* a [boolean](/types/boolean) value that is `true` if the game is paused or `false` if not.
+
+## Example
+
+Resume the game if it's paused and button **B** is pressed.
+
+```blocks
+input.onButtonPressed(Button.B, function () {
+	if (game.isPaused()) {
+        game.resume()
+    }
+})
+```
+
+## See also
+
+[is running](/reference/game/is-running),
+[is game over](/reference/game/is-game-over)

docs/reference/game/is-running.md

@@ -0,0 +1,28 @@
+# is Running
+
+Find out if the game is currently running or not.
+
+```sig
+game.isRunning()
+```
+
+## Returns
+
+* a [boolean](/types/boolean) value that is `true` if the game is running or `false` if not.
+
+## Example
+
+If the game is currently running, end the game if button **B** is pressed.
+
+```blocks
+input.onButtonPressed(Button.B, function () {
+	if (game.isRunning()) {
+        game.gameOver()
+    }
+})
+```
+
+## See also
+
+[is paused](/reference/game/is-paused),
+[is game over](/reference/game/is-game-over)