docs: Add URL in DESCRIPTION

Closes #12
2 jobs for master in 57 seconds (queued for 8 seconds)
Status Name Job ID Coverage
  Check
failed check #221378
docker

00:00:57

 
  Github
skipped github #221379
docker
 
Name Stage Failure
failed
check Check

❯ checking dependencies in R code ... NOTE
Namespace in Imports field not imported from: ‘config’
All declared Imports should be used.

1 error ✖ | 0 warnings ✔ | 2 notes ✖
Error: R CMD check found ERRORs
Execution halted
Cleaning up file based variables
ERROR: Job failed: exit code 1