Add favicon

Author: edongashi

_config.yml

@@ -12,7 +12,7 @@ footer_text: >
   Hosted by <a href="https://pages.github.com/" target="_blank">GitHub Pages</a>.
 keywords: Diffix, Anonymization, Privacy, Synthetic Data # add your own keywords or leave empty
 lang: en # the language of your site (for example: en, fr, cn, ru, etc.)
-icon: ⚛️ # the emoji used as the favicon (alternatively, provide image name in /assets/img/)
+icon: favicon.ico # the emoji used as the favicon (alternatively, provide image name in /assets/img/)
 
 url: https://diffix.github.io # the base hostname & protocol for your site
 baseurl: # the subpath of your site, e.g. /blog/