README: Minor tweaks

The `defaults read` output is not valid JSON, so use a different file
extension.

README.md

@@ -1,11 +1,16 @@
 # OSX Defaults
-A place to centralize the great work [@mathiasbynens](http://github.com/mathiasbynens/dotfiles/blob/master/.osx) did gathering and foster a community around finding and documenting OSX Default configuation from the command-line.
 
-Want to see *all*, and I mean **ALL** of the Default values on your system?
+A place to centralize the great work [@mathiasbynens](http://mths.be/osx) did gathering and foster a community around finding and documenting OS X default configuration from the command-line.
+
+Want to see *all*, and I mean **ALL** of the default values on your system?
 Open up your command line and type the following:
 
-`defaults read > ~/defaults.json`
+```bash
+defaults read > ~/defaults.txt
+```
 
 Just want the values for a specific application? 
 
-`defaults read -app iTerm`
+```bash
+defaults read -app iTerm
+```