Optional GitHub challenge needs expanding

[tobyhodges]

The optional exercise "Contributing to a page owned by someone else (slightly more complicated way)" in the GitHub Pages episode could be expanded, to include a more thorough explanation of the task and the motivation one might have for taking this "slightly more complicated" way to contributing to someone's project.

[emcaulay]

Thank you for this prompt, @tobyhodges ! I'll look into it this week to get oriented and will make further comments.

[drhansj]

I am trying to complete my instructor checkout and see this is still an open issue (on Carpentries help wanted), @tobyhodges could I take it over and wrap it up?

[alex-ball]

Thank you for raising this issue, @tobyhodges .

There are a few problems with that particular passage:

lc-git/episodes/05-github-pages.md

Lines 132 to 146 in ff8d8fb

	> ## Optional challenge: Contributing to a page owned by someone else (slightly more complicated way)
	>
	> Instead of making edits on the GitHub website you can 'clone' the fork to your local machine
	> and work there.
	::::::::::::::::::::::::::::::::::::::: challenge
	Try following the rest of the steps in this guide under ["Time to Submit Your First PR"](https://www.thinkful.com/learn/github-pull-request-tutorial/Writing-a-Good-Commit-Message#Time-to-Submit-Your-First-PR).
	(If you followed step 1 and 2 in the previous challenge,
	you already have a fork and you can skip the creation of a new fork.
	Start instead at the section titled "Cloning a fork."
	You can submit multiple pull requests using the same fork.)
	::::::::::::::::::::::::::::::::::::::::::::::::::

1. The heading and introductory paragraph should be inside the challenge fenced div, not before it in a block quote.
2. As you report, the introductory paragraph should explain why someone would want to do it.
3. Instead of taking learners through the steps directly, it tells them to look at an external set of instructions and adapt them on the fly. But the external instructions aren't there any more, as reported in issue Broken link to "Time to Submit Your First PR" #175.

We really need our own set of steps here that follow on from the previous challenge.

@drhansj , if you are still interested in addressing this issue, we'd welcome a pull request from you!