This commit updates the guidelines for increasing the Replication Factor
depending on whether tablets are enabled or disabled.
To present it in a clear way, I've reorganized the page.
Fixes https://github.com/scylladb/scylladb/issues/23667
Closes scylladb/scylladb#24221
(cherry picked from commit efce03ef43)
Closes scylladb/scylladb#24284