move shadow check spell to core

spells/Mind1.tex

@@ -21,13 +21,3 @@
     They take a -1 penalty to all actions using Mental Attributes, and a -1 \gls{ap} penalty during combat}% Description
   {}
 
-\spell{Shadow Check}% Name
-  {Fate, Water}% Spheres
-  {Witness}% Action
-  {}% Enhancements
-  {}% Resist with
-  {This spell tells the caster if any particular patch (and it has to be a specific patch) contains anything which has a mind}% Description
-  {Shadows, statues, or suspicious bushes can all hide all manner of things.
-
-    The spell will not say what kind of mind this is -- whether animal or person.
-    It reports only `yes/ no', and often has false positives due to mice or insects (1/6 chance in daylight, 2/6 chance at night).}