[webapp, docs]support en readme and webapp (#83)

* [docs]support en docs

* [docs]support en webapp

* [web-app]dashboard and monitor list i18n

* [web-app]i18n for monitor list

* [web-app]i18n for add edit monitor

* [web-app]i18n for monitor detail

* [web-app]i18n for login

* [web-app]i18n for alert center

* [web-app]i18n for alert notice

* [web-app]i18n for alert setting

* [web-app]i18n for notify

README.md

@@ -6,7 +6,7 @@
 
 [comment]: <> (<img alt="sureness" src="https://cdn.jsdelivr.net/gh/dromara/hertzbeat/home/static/img/hertzbeat-brand.svg" width="300">)
 
-## HertzBeat 赫兹跳动         
+## HertzBeat 赫兹跳动 | [English Documentation](README_EN.md)           
 
 > 易用友好的监控告警系统。