cleaned pkgdown site before building it

.github/workflows/check.yml

@@ -46,6 +46,7 @@ jobs:
         run: |
           git config --local user.email "[email protected]"
           git config --local user.name "GitHub Actions"
+          Rscript -e 'pkgdown::clean_site()'
           Rscript -e 'pkgdown::deploy_to_branch(new_process = FALSE)'
       - name: Build Gallery
         run: memoiR::knit_all()