track MacroUnquote -> Splice name change

Author: moritz

lib/X/TypeCheck/MacroUnquote.pod renamed to lib/X/TypeCheck/Splice.pod

@@ -1,8 +1,8 @@
 =begin pod
 
-=TITLE class X::TypeCheck::MacroUnquote
+=TITLE class X::TypeCheck::Splice
 
-    class X::TypeCheck::MacroUnquote is X::TypeCheck does X::Comp { }
+    class X::TypeCheck::Splice is X::TypeCheck does X::Comp { }
 
 Compile time error thrown when a L<Macro> or an unquote/hole in a C<quasi>
 quote does not return an L<AST>.
@@ -24,4 +24,13 @@ To fix, instead write
     }
     say a;              # foo
 
+=head1 Methods
+
+=head2 action
+
+    method action() returns Str:D
+
+Returns a verbal description of the action that triggered the error,
+C<"macro application"> or C<"unquote evaluation">.
+
 =end pod