Remove safe external dependencies

[nrichers]

Internal Notes for Reviewers

This is a companion PR to #146 that removes only those external dependencies that are safe to remove. It does this by:

• Locally storing fonts and updating how we import these fonts
• Removing other, unneeded external font references in our template schema docs

This PR should be merged as it reduces our dependencies and improves site loading times, as we no longer need to fetch our main font from Google every time we load the site.

There are no output changes to review, as the site largely looks almost exactly the same, except for the template schema docs that now use the same font as the rest of our docs site.

External Release Notes

To improve loading times and reduce the reliance on being connected to the internet, we removed some external dependencies for our docs site:

• Fonts are now stored and imported locally
• Other font references in our template schema docs have been removed