The following shows documentation that is currently missing on main:
?> git diff --diff-filter=D --summary 5.5.x:docs/manual/src/docs/asciidoc/_includes/servlet/integrations main:docs/modules/ROOT/pages/servlet/integrations/
delete mode 100644 concurrency.adoc
delete mode 100644 data.adoc
delete mode 100644 jackson.adoc
delete mode 100644 localization.adoc
They should be ported over.