Update readme.

Author: jcs090218

README.md

@@ -3,6 +3,12 @@
 [![MELPA Stable](https://stable.melpa.org/packages/dashboard-current-badge.svg)](https://stable.melpa.org/#/dashboard-current)
 [![License: GPL v3](https://img.shields.io/badge/License-GPL%20v3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0)
 
-
 # dashboard-current
 > Show files and directories in current directory.
+
+## Contribution
+
+If you would like to contribute to this project, you may either
+clone and make pull requests to this repository. Or you can
+clone the project and establish your own branch of this tool.
+Any methods are welcome!