add step to uncheck "copy the main branch only" to fork a lesson

[avallecam]

The chapter on fork and clone a lesson has more visibility to newcomers than the blog post that contains a really useful step to avoid extra steps and manual activation of GH-actions, as commented in previous issue.

Adding this step

https://github.com/carpentries/carpentries.org/blob/67e1b606e87d6f4533c9b8d164a3a7f5a6eb9002/_posts/2023/01/2023-01-17-dovetail-14.md?plain=1#L146-L147

After this step

sandpaper-docs/episodes/editing.md

Lines 38 to 39 in cad6ac6

	2. Go to https://github.com/carpentries/sandpaper-docs/fork/ to fork the repository
	to your account

Could be highly beneficial.

[zkamvar]

I absolutely agree. Sorry for the delay on that... I've been running on fumes since last year. I'll get a PR on that now.