Be careful to define terms "build" and "deploy"

[MichaelChirico]

I'm not sure the difference between the two, in particular I'm not sure why we would want to "build" without deploying? But just generally, these are very specific terms it might be better to introduce more carefully, even if that means just linking some other documentation.

Here's the first usage of build (outside function names):

https://github.com/r-lib/pkgdown/blob/676cf1dce39e4dc5aa1bcb671b1e14e992589a0a/vignettes/how-to-update-released-site.Rmd#L178

Here's the first usage of deploy:

https://github.com/r-lib/pkgdown/blob/676cf1dce39e4dc5aa1bcb671b1e14e992589a0a/vignettes/how-to-update-released-site.Rmd#L133