add a tips section to collect some good practices

diff --git a/README b/README
index d8741e68ecf8626ce94e5a3fe2b60a2b562ae202..c5b3432681c3306e6efb805eb0fec2408fa1b689 100644 (file)
--- a/README
+++ b/README
@@ -1,3 +1,7 @@
 http://www.seas.upenn.edu/~cis194/spring13/lectures.html
 
 Homework problems from CIS194 from Brent Yorgey.
+
+Tips:
+
+1. Use {-# OPTIONS_GHC -Wall #-} on all files.