Currently every PR opened from a fork results in a Netlify notification asking to approve the deploy preview; because many of our open source PRs are documentation related, it is convenient to see these builds often. Right now, we have sensitive environment variables for interacting with our MkDocs insiders repo so we don't want to use those for "untrusted" builds.

This PR attempts to change our Netlify build command so that it first attempts to install our Insiders package, but if that fails it falls back to a standard MkDocs build (which should work). We can then turn builds on for unknown authors that don't set sensitive environment variables. This should hopefully let us see useful deploy previews at the cost of not knowing if our insider builds are failing (this should be readily apparent though).

Example

Let's see how the deploy previews go in practice!

Checklist

• This pull request references any related issue by including "closes <link to issue>"
  • If no issue exists and your change is not a small fix, please create an issue first.
• This pull request includes tests or only affects documentation.
• This pull request includes a fix, feature, enhancement, docs, or maintenance label categorizing the change.