having weird chapter names doesnt work for leanpub

[carriewright11]

I was able to render just fine with ottr:

and the book.txt file included this as well (although I had named the chapter file elements.Rmd in the main repo):

Yet... it does not show up when leanpub renders the course:

this is all fine... I can rename my chapter to something less fun, but we should let people know that they cant do this - or it would be nice if the name of the md file didn't have to be the title but instead was something else.

[carriewright11]

you can see here that the name of the file for this chapter was elements.rmd to start with: fhdsl/Overleaf_and_LaTeX_for_Scientific_Articles#39