Allow Backend Specification of Displayable Cards

[GordonsKitchen]

Certain cards (mainly Garth One-Eye) can make copies of other cards. In a combo sense, this introduces cards to the combo, that don't need to be an individual card (or even in your deck). Many Garth combos use Black Lotus specifically. Because Black Lotus is not listed as a card in the combo, however, the image will not appear when you hover over its name throughout the steps. My understanding from Blade is that hover images are pulled exclusively from the cardlist of the combo - meaning that if it isn't in the list, it won't show up. Then again, you don't need Black Lotus as an individual card - so putting it as a card in the combo is not preferable.

The suggestion would be to make some sort of function in the back-end which would allow head-editors to manually specify a list of cards that will show up when you hover over their names. So, in cases of Garth, we can still have Black Lotus, Braingeyser, and the others show up as needed without them needing to be added.

(Originally requested by DarthJeeling)

[ldeluigi]

Another idea: we integrate the [[]] notation in the frontend, inside the description syntax so that [[Black Lotus]] gets the image when you hover, without touching the backend