Prefetch Google fonts in Gatsby site

[carolstran]

There was a discussion in #924 about whether we should import or prefetch the Google fonts used for the website. This PR was to the new Gatsby version of graphql.org.

A few options were proposed/explored:

• Importing the fonts via CSS (which was proposed in the original PR)
• Prefetching with gatsby-plugin-prefetch-google-fonts (but unfortunately it has been archived)
• Prefetching with a community fork of the above package (but ran into errors)

Ultimately, we decided to import the fonts and then optimize performance/implement prefetching in a future PR. So this issue serves as a reminder for that 😇

[saihaj]

As discussed in this issue gatsbyjs/gatsby#10475 (comment) we should host the font in static dir and then to preload them we can use gatsby-plugin-preload-fonts

[mikeesto]

#938 uses gatsby-plugin-webfonts (there are so many font plugins 😅 ) to self host the fonts so I think this can be closed now.

[Urigo]

Thanks @mikeesto !
closing