doc: add badge for edge add-on

README.md

@@ -3,6 +3,7 @@ Violentmonkey
 
 [![Chrome Web Store](https://img.shields.io/chrome-web-store/v/jinjaccalgkegednnccohejagnlnfdag.svg)](https://chrome.google.com/webstore/detail/violentmonkey/jinjaccalgkegednnccohejagnlnfdag)
 [![Firefox Add-ons](https://img.shields.io/amo/v/violentmonkey.svg)](https://addons.mozilla.org/firefox/addon/violentmonkey)
+[![Microsoft Edge Add-on](https://img.shields.io/badge/dynamic/json?label=microsoft%20edge%20add-on&query=%24.version&url=https%3A%2F%2Fmicrosoftedge.microsoft.com%2Faddons%2Fgetproductdetailsbycrxid%2Feeagobfjdenkkddmbclomhiblgggliao)](https://microsoftedge.microsoft.com/addons/detail/eeagobfjdenkkddmbclomhiblgggliao)
 [![Gitter](https://img.shields.io/gitter/room/violentmonkey/violentmonkey.svg)](https://gitter.im/violentmonkey/violentmonkey)
 [![TravisCI](https://travis-ci.org/violentmonkey/violentmonkey.svg?branch=master)](https://travis-ci.org/violentmonkey/violentmonkey)