Fix grammar in README

README.md

@@ -13,7 +13,7 @@ Gogs - Go Git Service [![Build Status](https://travis-ci.org/gogits/gogs.svg?bra
 
 ### Important Notes
 
-1. **YOU MUST READ [Contributing Code](https://github.com/gogits/gogs/wiki/Contributing-Code) BEFORE START WORKING ON PULL REQUEST**.
+1. **YOU MUST READ [Contributing Code](https://github.com/gogits/gogs/wiki/Contributing-Code) BEFORE STARTING TO WORK ON A PULL REQUEST**.
 2. Due to testing purpose, data of [try.gogs.io](https://try.gogs.io) was reset in **Jan 28, 2015** and will reset multiple times after. Please do **NOT** put your important data on the site.
 3. The demo site [try.gogs.io](https://try.gogs.io) is running under `develop` branch.
 4. If you think there are vulnerabilities in the project, please talk privately to **u@gogs.io**. Thanks!