Transition to Quarto built-in solution for GitHub "Edit this page" links, when available

[ravicodelabs]

As of 1/19/23, Quarto was coupling its table of contents feature (toc) with its GitHub "Edit this page" feature. Since we don't always use a toc, there isn't a straightforward way for us to have the "Edit this page" link on pages without the toc. And, the placement of the "Edit this page" link is also restricted because of this coupling.

As a workaround, we created a post-render script render_scripts/github_link_insertion.ts to insert the GitHub links. Once the Quarto project adds the appropriate functionality in, we can transition to a Quarto built-in solution rather than maintain the custom post-render script.

Related Quarto issue: quarto-dev/quarto-cli#2142
Related DataSciJEDI issue: #35

(Moved from the #115).