[WHO] Implement Astrid Peth, Jenny Flint, Madame Vastra

[Susucre]

All three being simple implementation, grouped them together in this PR.

[github-actions]

Astrid Peth - (Gatherer) (Scryfall) (EDHREC)

{1}{W}
Legendary Creature — Human
2/2
Whenever Astrid Peth enters the battlefield or attacks, create a Food token.
Brand-new Sky — Whenever you sacrifice a Clue or Food, Astrid Peth explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Jenny Flint - (Gatherer) (Scryfall) (EDHREC)

{1}{U}{R}
Legendary Creature — Human Detective
2/2
Partner with Madame Vastra
First strike
Training (Whenever this creature attacks with another creature with greater power, put a +1/+1 counter on this creature.)
Whenever you sacrifice a Clue or Food, put a +1/+1 counter on another target creature you control.

Madame Vastra - (Gatherer) (Scryfall) (EDHREC)

{2}{G}{U}
Legendary Creature — Lizard Detective
3/3
Partner with Jenny Flint (When this creature enters the battlefield, target player may put Jenny Flint into their hand from their library, then shuffle.)
Madame Vastra must be blocked if able.
Whenever a creature dealt damage by Madame Vastra this turn dies, create a Clue token and a Food token.