Update instructions for configuring a GitHub Pages source

[parkerbxyz]

Changes are now saved immediately after selecting a publishing source.

Official docs for reference: Configuring a publishing source for your GitHub Pages site.

[parkerbxyz]

I'm not sure why the deployments are failing, so I'm going to leave this PR in a draft state until someone tells me it is safe to merge.

[brianamarie]

Hmm @parkerbxyz I'm not sure why the deploy is failing. @JasonEtco where can we look to get some more context on why this is failing? Could it be because it's a draft PR?

@parkerbxyz I think it's OK to try this as a non-draft PR to see if that affects the deploy. What do you think?

[brianamarie]

I don't know what's up with the deploy message. I am able to access the deployed version of this branch: https://lab.github.com/githubtraining/securing-your-workflows/12.3.1-parkerbxyz-patch-1.0, and I'm also able to register for the course: brianamarie/security-on-github#2.

I say 🚢 this @parkerbxyz - worst case scenario is that it doesn't deploy, so it won't break anything that isn't already broken, and we can troubleshoot from there.

[parkerbxyz]

Alright, I'll go ahead and merge. Thanks, @brianamarie!