Add install instructions.

cfg/monster_precache.cfg

@@ -1,6 +1,8 @@
 //
 // MONSTERS - monsters that you always want to precache (for dynamic spawning)
 //
+// Install this file to your mod's base directory.
+//
 // (just remove the comment characters at the beginning of the line for the
 //  monsters that you always want to precache.)
 

cfg/monster_skill.cfg

@@ -1,6 +1,6 @@
 // MONSTERS health and damage amounts
 //
-// (Note: Some of these aren't currently used.  They're in here for future use.)
+// Install this file to your mod's base directory.
 
 // Alien Grunt
 sk_agrunt_health			90