remove pdf/epub download and "Edit" from toolbar

[lheagy]

Currently, the links for the pdf / epub from the toolbar lead to a "Page not found"

• pdf: https://ubc-dsci.github.io/introduction-to-datascience/_main.pdf
• epub: https://ubc-dsci.github.io/introduction-to-datascience/_main.epub

Should these be available to download? or should we disable the download links to avoid confusion?

[trevorcampbell]

These aren't (and can't, I believe, for contractual reasons) be available.

We should definitely remove these links in the HTML render if we can (a few students every semester get confused by this)

[trevorcampbell]

Related: the "edit" button in the toolbar points here to a broken URL: https://github.com/rstudio/bookdown-demo/edit/master/index.Rmd

[trevorcampbell]

I think the index.Rmd example on the following page shows how to disable it, not sure if it gets removed entirely:

https://bookdown.org/yihui/bookdown/html.html

testing now

[trevorcampbell]

OK, PR opened #418

[lheagy]

Thanks @trevorcampbell!

[trevorcampbell]

Done as of d10e86a