Allow bombs to explode other bombs

modules/game/actors.scm

@@ -371,7 +371,7 @@
                              ((obj . rest) obj))))
                   (when obj
                     (match ($ obj 'type)
-                      ('brick
+                      ((or 'bomb 'brick)
                        ($ obj 'explode))
                       ('player
                        ($ obj 'explode)
@@ -388,6 +388,7 @@
        ($ countdown 2)))
     (('alive?) ($ alive?))
     (('describe) `(bomb ,($ position) ,($ countdown)))
+    (('explode) ($ countdown 2))
     (('collide other offset grid-info)
      (when (eq? ($ other 'type) 'player)
        (match ($ position)