In the Introduction chapter, under Using this manual (https://koha-community.org/manual/latest/en/html/intro.html#using-this-manual) there are a couple of references to the koha-docs mailing list. This list does not exist anymore. We should remove those references since if someone reports an error or missing information, we just tell them to open a bug report on bugzilla. We can maybe add a reference to the general mailing list and mattermost where people can discuss questions about using Koha that are not answered in the manual.