include main branch

[wibeasley]

to help people using this yaml file as a starting point in a new GitHub repo

[hadley]

Thanks for working on this but we’re going to tackle globally in #512

[wibeasley]

#512 seems similar, but not quite the same. It's talking about moving this specific repo from master to main, right?

This change is focused on people using Mastering Shiny as a starting point for their bs4_book build, as advocated in the current bookdown book section 3.1.2 Three-column Bootstrap style

The bs4_book() output format is built with Bootstrap ... You can read an example book here: https://mastering-shiny.org

I'm basically updating this workflow yaml so it's consistent will the ones I've seen @jimhester use since GitHub started advocating the main branch a year ago. https://github.com/tidyverse/readr/blob/7ded0b0f0f39e8429163e9467f3c727b28036c8c/.github/workflows/pkgdown.yaml#L1-L5

[hadley]

It’s all part of the same general problem.