#enhance docs again

Since "weapons and spell skills" is grammatically suspect and
"weapons and spells skills" sounds odd, change to "weapon and spell skills"
in both the Guidebook and the game's online descriptions.  The #enhance
command itself uses "current skills" and doesn't need any alteration.

dat/hh

@@ -88,7 +88,7 @@ M-2     twoweapon toggle two-weapon combat (unless number_pad is enabled)
 M-a     adjust  adjust inventory letters
 M-c     chat    talk to someone
 M-d     dip     dip an object into something
-M-e     enhance advance or check weapons or spell skills
+M-e     enhance advance or check weapon and spell skills
 M-f     force   force a lock
 M-i     invoke  invoke an object's special powers
 M-j     jump    jump to another location