Update README.md

README.md

@@ -1,14 +1,22 @@
 Sugar [![Build Status](https://travis-ci.org/mbutterick/sugar.svg?branch=master)](https://travis-ci.org/mbutterick/sugar)
 -----
 
-Functions that improve the readability of Racket code.
+Functions that improve the readability of Racket code in Racket 6.0+.
 
-Using Racket 6.0+, install from the command line like so:
+Install from the command line like so:
 
     raco pkg install sugar
 
-And update like so:
+Then require it in your Racket file, in standard mode:
 
-    raco pkg update sugar
+    (require sugar)
+    
+In safe mode (with contracts):
+
+    (require (submod sugar safe))
+
+Or in typed mode:
+
+    (require typed/sugar)
 
 You can [read the docs here](http://pkg-build.racket-lang.org/doc/sugar).