feat: Swagger docs for `/pay` endpoints #3024

Job	Run time
Check file changes	4s
Build React App	6s
Run API Tests	49s
Run Integration tests	5m 4s
E2E tests	8m 31s
Generate Hasura Change Summary	0s
Run React Tests	0s
Upsert Vultr Instance	10m 12s
Run Pulumi Preview	0s
Run Healthcheck on Pizza Services	0s
	24m 46s

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