I am starting to create Wiki in my TFS 2018 Update 2 and I find the problem of making full searches of both the content of the wiki and the attachments you may have (content of PDF, DOCX, etc). Is it possible to enable the search function within the attachments?
I'd appreciate your help
This is not possible for now. You can use wiki search to quickly find relevant wiki pages by title or page content across all projects in your TFS.
Take a look at this blog contain the detail Introduction-- Announcing public preview of Wiki search
If you really need this feature, you could submit a uservoice here, TFS PM and Admin will kindly review your suggestion.