Include book folder in link check

Author: spier

.github/workflows/link-checker.yml

@@ -21,6 +21,6 @@ jobs:
       id: lc
       uses: peter-evans/link-checker@v1
       with:
-        args: -v -d . -x "http://creativecommons.org/licenses|https://isc-inviter.herokuapp.com|https://github.com/rcs/rcs-viewer/pull/81|fearlesschangepatterns.com|https://ulir.ul.ie/bitstream/handle/10344/4443/Stol_2014_inner.pdf|https://docs.github.com/en/rest/metrics/statistics|https://docs.github.com/en/rest/search#search-repositories" README.md patterns/ translation/ -r
+        args: -v -d . -x "http://creativecommons.org/licenses|https://isc-inviter.herokuapp.com|https://github.com/rcs/rcs-viewer/pull/81|fearlesschangepatterns.com|https://ulir.ul.ie/bitstream/handle/10344/4443/Stol_2014_inner.pdf|https://docs.github.com/en/rest/metrics/statistics|https://docs.github.com/en/rest/search#search-repositories" README.md patterns/ book/ translation/ -r
     - name: Fail if there were link errors
       run: exit ${{ steps.lc.outputs.exit_code }}