📝 Update README

Author: risacan

README.md

@@ -1,3 +1,7 @@
 # chrome-extension-waffleio
 
-Trelloぽくwaffleioの背景色を変更するChrome Extensionです。
+This is a chrome extension that changes [waffle.io](https://waffle.io)'s background color like Trello.
+
+# Install
+1. Download Latest package from [here](https://github.com/risacan/chrome-extension-waffleio/releases).
+1. Open Chrome extension page (Enter `chrome://extensions/` into the address bar) and drag the downloaded package.