Move 'snippet' queries to 'snippets' folders

cpp/ql/examples/snippets/mutualrecursion.ql

@@ -0,0 +1,16 @@
+/**
+ * @name Mutual recursion
+ * @description Finds pairs of functions that call each other
+ * @tags function
+ *       method
+ *       recursion
+ */
+
+import cpp
+
+from Function m, Function n
+where
+  exists(FunctionCall c | c.getEnclosingFunction() = m and c.getTarget() = n) and
+  exists(FunctionCall c | c.getEnclosingFunction() = n and c.getTarget() = m) and
+  m != n
+select m, n