Make "Get Pages failed" error message more helpful

[WofWca]

I was setting up gh-pages deployment as a GitHub action from the very beginning, and the error was confusing.

[JamesMGreene]

👋🏻 Just wanted to drop a quick note to say that I see your PR, and I appreciate it and its intent. 🙇🏻

That said, I do want to hold off on it until I get a chance to test this experience more thoroughly, as I'm a bit confused as to the specific configuration that must've been in place to trigger this error.

Did you perhaps run the workflow before enabling Pages at the repository level? 🤔

[WofWca]

Did you perhaps run the workflow before enabling Pages at the repository level?

Well, yes. I made a fork of a repo (that didn't have GitHub Pages) and went straight for creating the GitHub action, without doing anything else, without going to settings or deploying the gh-pages branch manually.

[JamesMGreene]

@WofWca Gotcha! Thanks for helping me understand the setup. 🙇🏻

[JamesMGreene]

This has been released in the latest version:

uses: actions/configure-pages@f156874f8191504dae5b037505266ed5dda6c382
uses: actions/configure-pages@v3.0.6
uses: actions/configure-pages@v3
uses: actions/configure-pages@main

[JamesMGreene]

Thanks again for the PR, @WofWca! That error message will definitely help some folks avoid this confusion in the future. 💝