Move FAQs' Content to the Manual

[brishtibheja]

By the way, I recall talk of content in the FAQs page vs the manual, but not sure where I saw it. Recently, I've come to feel that a FAQ page is more a convenience for support people, and the info is better placed in the manual instead. In the future, I'd like to see us improving the manual, and removing the entries of the FAQ page.

(Originally posted in ankitects/faqs#36 (comment))

[brishtibheja]

A good start might be to move these pages here and here to the manual. There is already a Checks and Errors section in the manual.

@dae thoughts? They'll become sub-sub-sections of card-template section. FYI, the FAQ pages I'm linking to is used in desktop error messages. The PR was merged recently.

[dae]

That's fine, but old Anki versions directly link to the old pages, so we'll probably want to either keep around the old pages and have them link to the new location (latter is better for maintenance)