specialties: point to valid examples

Library/Homebrew/formula_specialties.rb

@@ -1,13 +1,13 @@
 # Base classes for specialized types of formulae.
 
-# See youtube-dl.rb for an example
+# See chcase for an example
 class ScriptFileFormula < Formula
   def install
     bin.install Dir['*']
   end
 end
 
-# See flac.rb for an example
+# See browser for an example
 class GithubGistFormula < ScriptFileFormula
   def initialize name='__UNKNOWN__', path=nil
     url = self.class.stable.url