Added font-display: auto to _fonts.scss
Added font-display: auto to _fonts.scss

font-display on `auto` makes sure that the text is always
visible for the user. It's a suggestion by Googles PageSpeed Insights
to activate this feature:

https://developers.google.com/web/updates/2016/02/font-display?utm_source=lighthouse&utm_medium=unknown

Signed-off-by: Christian Rebischke <711c73f64afdce07b7e38039a96d2224209e9a6c@nullday.de>

MSF-Jarvis/msf-jarvis.github.io