Update description of filtered-deck delays [manual & FAQ]

[Danika-Dakika]

In the manual, and in the FAQ for filtered decks with rescheduling disabled, there are specific delay-timing rules for the buttons (as of the v3 scheduler).

Filtered decks with rescheduling disabled now show 4 buttons - the provided delay applies to the Again button, and Hard/Good will use 1.5x and 2x the provided delay. Easy will remove the card.

But as of 23.12, the delay-timing is customizable.

When rescheduling is disabled in a filtered deck, you can now choose different delays for again, hard and good. Set to 0 to have that button immediately remove the card.

[Danika-Dakika]

Looks like the "Rescheduling" header (https://docs.ankiweb.net/filtered-decks.html#rescheduling) on this page might be a piece of this as well. Perhaps that should merge with "Steps & Returning"?

[Is there a way to preserve/redirect jump links and page links so that we don't dead-link old help responses?]

[dae]

<a id="my-anchor"></a> can be used to create an anchor with an old name, if we rename the heading.

[brishtibheja]

Was this fixed in the changes made for #272? The said lines were removed.