Fix Jenkinsfile: Update volume mount path for HTML output directory

Signed-off-by: Stephen Simpson <ssimpson89@users.noreply.github.com>

Jenkinsfile

@@ -99,7 +99,7 @@ mkdir -p ./html ./tmp
 
 # Run the container to build man pages
 docker run --rm \
-  -v "$(pwd)/html:/app/html" \
+  -v "$(pwd)/html:/data/html" \
   -v "$(pwd)/tmp:/data/tmp" \
   rocky-man:${BUILD_NUMBER} \
       --versions ${VERSIONS} \