Tweak rdrr.io links in pkgdown docs

[galachad]

pharmaverse/admiralci Proposal to solve linking issue between packages.

• Place Closes #<insert_issue_number> into the beginning of your Pull Request Title (Use Edit button in top-right if you need to update)
• Code is formatted according to the tidyverse style guide. Run styler::style_file() to style R and Rmd files
• Updated relevant unit tests or have written new unit tests - See Unit Test Guide
• If you removed/replaced any function and/or function parameters, did you fully follow the deprecation guidance?
• Update to all relevant roxygen headers and examples.
• Run devtools::document() so all .Rd files in the man folder and the NAMESPACE file in the project root are updated appropriately
• Address any updates needed for vignettes and/or templates
• Update NEWS.md if the changes pertain to a user-facing function (i.e. it has an @export tag) or documentation aimed at users (rather than developers)
• Build admiral site pkgdown::build_site() and check that all affected examples are displayed correctly and that all new functions occur on the "Reference" page.
• Address or fix all lintr warnings and errors - lintr::lint_package()
• Run R CMD check locally and address all errors and warnings - devtools::check()
• Link the issue so that it closes after successful merging.
• Address all merge conflicts and resolve appropriately.
• Pat yourself on the back for a job well done! Much love to your accomplishment!

[galachad]

Closed, as implemented globally in admiralci for all admiral package ecosystem. pharmaverse/admiralci#141