readme: lowercase git

jeffkaufman · jeffkaufman · commit 5cef9cd98596 · 2014-12-09T09:45:16.000-05:00
diff --git a/README.md b/README.md
@@ -39,7 +39,7 @@ Show differences between files in a two column view.
 ```
 
 
-## Using with GIT
+## Using with git
 
 To see what it looks like, try:
 
