Allow missing docs

Author: richardreeve

.github/workflows/pkgdown.yaml

@@ -47,4 +47,4 @@ jobs:
         run: |
           git config --local user.email "[email protected]"
           git config --local user.name "GitHub Actions"
-          Rscript -e 'pkgdown::deploy_to_branch(new_process = FALSE)'
+          Rscript -e 'Sys.unsetenv("CI"); pkgdown::deploy_to_branch(new_process = FALSE)'