commands: add formatting to headings

Library/Homebrew/cmd/commands.rb

@@ -35,21 +35,18 @@ module Homebrew
     end
 
     # Find commands in Homebrew/cmd
-    puts "Built-in commands"
-    puts Formatter.columns(internal_commands.sort)
+    ohai "Built-in commands", Formatter.columns(internal_commands.sort)
 
     # Find commands in Homebrew/dev-cmd
     puts
-    puts "Built-in developer commands"
-    puts Formatter.columns(internal_developer_commands.sort)
+    ohai "Built-in developer commands", Formatter.columns(internal_developer_commands.sort)
 
     exts = external_commands
     return if exts.empty?
 
     # Find commands in the PATH
     puts
-    puts "External commands"
-    puts Formatter.columns(exts)
+    ohai "External commands", Formatter.columns(exts)
   end
 
   def internal_commands