GS Ch8 (Base) for a future book

I have put flywire's reviewed copy of GS Ch8 (Base) in a folder called
"Future book suggestions" under Getting Started Guides in NextCloud. I
have copied flywire's email into that reviewed copy, so the comments
are not lost.

I have made minor amendments to the draft 7.3 chapter following
flywire's review and put it in GS 7.3 Work in Progress.