readme improvements

README.rdoc

@@ -1,6 +1,7 @@
 = Letter Opener
 
-Preview mail in your browser instead of sending it. When using the included delivery method, any sent mail will open automatically into the browser.
+Preview email in the browser instead of sending it. This means you do not need to set up email delivery in your development environment, and you no longer need to worry about accidentally sending a test email to someone else's address.
+
 
 == Rails Setup
 
@@ -12,12 +13,12 @@ Then set the delivery method in <tt>config/environments/development.rb</tt>
 
   config.action_mailer.delivery_method = :letter_opener
 
-Now any delivered mail will pop up in your browser. The messages are stored in <tt>tmp/letter_opener</tt>.
+Now any email will pop up in your browser instead of being sent. The messages are stored in <tt>tmp/letter_opener</tt>.
 
 
-== Other Setup
+== Non Rails Setup
 
-This can be used with anything that uses the Mail gem. Simply set the delivery method when configuring Mail and specify a location.
+If you aren't using Rails, this can be easily set up with the Mail gem. Just set the delivery method when configuring Mail and specify a location.
 
   require "letter_opener"
   Mail.defaults do