Merge branch 'docs-lint-readme-error' into 'master'

Docs lint readme error

See merge request gitlab-org/gitlab!36508

scripts/lint-doc.sh

@@ -48,7 +48,8 @@ echo
 if [ ${FIND_READMES} -ne $NUMBER_READMES ]
 then
   echo
-  echo '  ✖ ERROR: New README.md file(s) detected, prefer index.md over README.md.' >&2
+  echo '  ✖ ERROR: The number of README.md file(s) has changed. Use index.md instead of README.md.' >&2
+  echo '  ✖        If removing a README.md file, update NUMBER_READMES in lint-doc.sh.' >&2
   echo '  https://docs.gitlab.com/ee/development/documentation/styleguide.html#work-with-directories-and-files'
   echo
   ((ERRORCODE++))