Ask Google not to translate website (#24)

Google may analyse sensitive content for
the purpose of recognising whether the page needs to be translated, see
https://support.google.com/webmasters/answer/79812?hl=en

public/index.html

@@ -8,6 +8,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
     <meta name="theme-color" content="#ffc107">
 
+    <meta name="google" content="notranslate">
     <meta name="referrer" content="no-referrer">
     <meta name="apple-mobile-web-app-capable" content="yes">
     <meta name="apple-mobile-web-app-title" content="EteSync">