Avoid hiding Crystal module from docs

Brian J. Cardiff · Brian J. Cardiff · commit b4b701a5caf6 · 2017-06-05T00:40:24.000-03:00
diff --git a/src/crystal/system/random.cr b/src/crystal/system/random.cr
@@ -1,4 +1,3 @@
-# :nodoc:
 module Crystal
   # :nodoc:
   module System
