add_card: Add cards to a deck
In zachary-foster/flashcards: Functions to Create and Practice Digital Flashcards

Add cards to a deck

1 2	add_card(deck_path, front, back, difficulty = 1, source = "", source_url = "", rename_img = TRUE, max_pixels = 6e+05)

`deck_path`	The path to the deck folder
`front`	The front of the cards to add
`back`	The back of the cards to add
`difficulty`	A positive number, typically between 1 and 10, indicating the difficulty of the card. Lower difficulties will typically be presented first.
`source`	Where the information came from the copyright holder of images
`source_url`	The location on the internet the infromation came from
`rename_img`	If `TRUE`, rename the image files based on the other side of the card.
`max_pixels`	The maximum number of pixels an image can be. Larger images will be shrunk to this size and saved as a jpeg.