Augment port description.

svn path=/head/; revision=284300

games/battletanks/pkg-descr

@@ -3,11 +3,18 @@ three vehicles and eliminate your enemy using the whole arsenal of weapons.
 It has original cartoon-like graphics and cool music, its fun and dynamic,
 it has several network modes for deathmatch and cooperative -- what else is
 needed to have some fun with your friends?  And all is packed and ready for
-you in Battle Tanks.  Features include:
+you in Battle Tanks.  Some of the game highlights:
 
-    - Multiplayer
-    - Cross-platform
-    - Free distribution and open source
-    - Old-school oriented
+  * Three vehicles: tank, Shilka, and rocket launcher, each having its
+    special features
+  * Lots of weapons: four types of ammo, six types of rockets, landing
+    troops, mines, etc.
+  * 13 multiplayer maps (nine ones for deathmatch and four ones for
+    cooperative mode) in different locations such as city, village, forest,
+    desert, etc.
+  * Game world that reacts on player: roads have traffic, buildings can be
+    destroyed, weather effects are simulated
+  * Lots of war objects: troops, vehicles, helicopters, etc.
+  * Keyboard and gamepad are supported
 
 WWW: http://btanks.sourceforge.net/