Unit test failure following digest DESCRIPTION change

[eddelbuettel]

The digest package has long had a material for mkdocs-driven documentation site at https://eddelbuettel.github.io/digest. This is now generated via altdoc by @etiennebacher. And I learned from him and @jeroen that in order to have r-universe link to such a site I needed a top-level pkgdown.yml which is now produced. But, to please how altdoc operates (or possibly operated) I re-ordered the URL links in the DESCRIPTION file of digest which now reads

URL: https://github.com/eddelbuettel/digest, https://eddelbuettel.github.io/digest/, https://dirk.eddelbuettel.com/code/digest.html

and that apparently throws a spanner at the test in

https://github.com/r-lib/downlit/blob/cdaa2f13263892890b6aa4d636982e9e9e645229/tests/testthat/test-link.R#L216-L219

as seen in

    ══ Failed tests ════════════════════════════════════════════════════════════════
    ── Failure ('test-link.R:216:3'): looks in attached packages ───────────────────
    href_expr_(vignette("sha1")) (`actual`) not equal to "https://cran.rstudio.com/web/packages/digest/vignettes/sha1.html" (`expected`).
    
    `actual`:   "https://eddelbuettel.github.io/digest/vignettes/sha1.html"       
    `expected`: "https://cran.rstudio.com/web/packages/digest/vignettes/sha1.html"

This is currently holding up digest at CRAN. We will see how this turns out, @uligges and @kurthornik may decide to let the package pass, or they may ask me to arrange for downlit to be upgraded. Which it needs to eventually anyway so here is your heads-up, I think I will send you a convenience PR in a moment too.