games: Add documentation

This commit add support to Games documentation on NuttX.

Signed-off-by: Alan Carvalho de Assis <[email protected]>

Documentation/applications/games/index.rst

@@ -2,4 +2,17 @@
 Games
 =====
 
-- shift - Shift Game
+NuttX is not only an RTOS, it is a rich ecosystem with much fun.
+And for many people fun is related to games! So let's play!
+
+Here you will find the list of games currently supported by NuttX.
+
+An interesting fact is that originally NuttX had the Traveler game.
+It is a raycasting game that Greg Nutt developed from scratch, similar
+to Doom in many ways. That game is not part of Apache NuttX.
+
+.. toctree::
+  :maxdepth: 2
+  :caption: Contents
+
+  brichmatch.rst