Update readme for safari.

Author: rebornix

README.md

@@ -2,7 +2,7 @@
 
 > Authenticator generates 2-Step Verification codes in your browser.
 
-## Available for Chrome, Firefox, and Microsoft Edge
+## Available for Chrome, Firefox, Microsoft Edge and Safari
 
 [<img src="https://raw.githubusercontent.com/wiki/Authenticator-Extension/Authenticator/readme-images/chrome-web-store.png" title="Chrome Web Store" width="170" height="48" />](https://chrome.google.com/webstore/detail/authenticator/bhghoamapcdpbohphigoooaddinpkbai) [<img src="https://raw.githubusercontent.com/wiki/Authenticator-Extension/Authenticator/readme-images/firefox-add-ons.png" title="Firefox Add-ons" width="170" height="48" />](https://addons.mozilla.org/en-US/firefox/addon/auth-helper?src=external-github) [<img src="https://raw.githubusercontent.com/wiki/Authenticator-Extension/Authenticator/readme-images/microsoft-store.png" title="Microsoft Store" height="48">](https://microsoftedge.microsoft.com/addons/detail/ocglkepbibnalbgmbachknglpdipeoio) [<img width="150" alt="Download on the App Store" src="https://developer.apple.com/assets/elements/badges/download-on-the-app-store.svg"/>](https://apps.apple.com/us/app/authen/id1602945200?mt=12)
 
@@ -22,6 +22,8 @@ npm ci
 npm run prod
 ```
 
+To reproduce a build for Safari, please follow contribution guidance in [Authenticator-Extension/Authen](https://github.com/Authenticator-Extension/Authen#how-to-contribute)
+
 ## Development (Chrome)
 
 ``` bash