Add introduction for this project

README.md

-# jenkins-cli
-Jenkins cli
+# Jenkins CLI
+
+Jenkins CLI allows you manage your Jenkins as an easy way. No matter you're a plugin
+developer, administrator or just a regular user, it borns for you!
+
+# Features
+
+* Multiple Jenkins support
+* Plugins manage
+
+# Get started
+
+For the mac user, you just need one command then you can own it.
+
+`brew install linuxsuren/jenkins-cli/jcli`
+
+# Contribution
+
+It's still under very early develope time. Any contribution is welcome.