Add flag of Quebec

Include flag of the Canadian province of Quebec (`ca-qc`).

Depending on how much you want to simplify the _fleur-de-lis,_ here is my version:
<img alt="" width="128" src="https://user-images.githubusercontent.com/16606427/234666805-63625648-3b00-4c1a-aa33-110d62feee8a.svg">