place coinage in rules category

glossary.tex

@@ -851,6 +851,7 @@ Set the darker die to `\dicef{6}' and roll the other.  If this roll fails, it fa
   shortplural={cp},
   name={Copper Pieces ({\scshape cp})},
   type={mech},
+  category={rules},
   longplural={copper pieces},
   prefix={a\space},
   parent={coin},
@@ -861,6 +862,7 @@ Set the darker die to `\dicef{6}' and roll the other.  If this roll fails, it fa
   name={Silver Pieces ({\scshape sp})},
   sort={Y},
   type={mech},
+  category={rules},
   longplural={silver pieces},
   shortplural={sp},
   prefix={a\space},
@@ -874,6 +876,7 @@ Set the darker die to `\dicef{6}' and roll the other.  If this roll fails, it fa
   longplural={gold pieces},
   sort={Z},
   type={mech},
+  category={rules},
   prefix={a\space},
   parent={coin},
 ]{gp}{gp}{Gold Piece}