Deprecate outdated workflows

[hadley]

Fixes #2427

@jennybc similarly few test for deprecation messages here because these functions are hard to test (and we never invested in making them easier). So I think if you skim the docs and try out a couple that should be adequate.

[jennybc]

LGTM!

I kinda wish we had a way to pause execution at the same place as lifecycle::deprecate_warn() and give the user the chance to back out and do the recommended thing. But that's more of a discussion point and idea for the future than a comment on this PR.

Motivation: look at how the deprecation warning appears below. It's (a) extremely easy to miss and not learn from and (b) you only see the suggested new move after the old deprecated one has happened.

> create("~/tmp/deleteme")
✔ Creating /Users/jenny/tmp/deleteme/.
✔ Setting active project to "/Users/jenny/tmp/deleteme".
✔ Creating R/.
✔ Writing DESCRIPTION.
Package: deleteme
Title: What the Package Does (One Line, Title Case)
Version: 0.0.0.9000
Authors@R (parsed):
    * Jennifer Bryan <jenny@posit.co> [aut, cre] (ORCID: <https://orcid.org/0000-0002-6983-2759>)
Description: What the package does (one paragraph).
License: MIT + file LICENSE
Encoding: UTF-8
Roxygen: list(markdown = TRUE)
RoxygenNote: 7.3.3
✔ Writing NAMESPACE.
✔ Writing deleteme.Rproj.
✔ Adding "^deleteme\\.Rproj$" to .Rbuildignore.
✔ Adding ".Rproj.user" to .gitignore.
✔ Adding "^\\.Rproj\\.user$" to .Rbuildignore.
✔ Setting active project to "<no active project>".
Warning message:
`create()` was deprecated in devtools 2.5.0.
ℹ Please use `usethis::create_package()` instead.
This warning is displayed once per session.
Call lifecycle::last_lifecycle_warnings() to see where this warning was generated.

[hadley]

It's a little easier interactively because you see the colours, but I take your point. Definitely more of an issue with these interactive only function than the usual deprecation fodder.