Function: new_card

--Usage--
> new_card(map_of_field_names_to_values)

Create a new [[type:card]] object not already in the set.

The argument is a map of values to set, for example @new_card([name: "My Card"])@ creates a card with the name @"My Card"@, and all other fields at their default value.

NOTE: you should use underscores instead of spaces in field names.

--Parameters--
! Parameter	Type							Description
| @input@	[[type:map]] of field names to field values		Field values to set
| @ignore_field_not_found@	[[type:boolean]]		Optional. If set to true, key/value pairs that don't correspond to a card field will be ignored instead of throwing.

--Examples--
> # Create a new card
> my_card := new_card(
>      [ name: "My Card"
>>      , type: "Super cool"
>>      , rule_text: "This card is <i>mine</i>!"
>      ])
> 
> # Write an image of the card to a file
> write_image_file(my_card, file: "my_card.jpg")
