Update README.MD

payment/README.MD

@@ -1 +1,16 @@
-# Payment service
+# Payment service
+Payment service is the adaptor that connects to IDPay in and logs all of the payments.
+
+## Compiling
+Compiling is easy with go 1.21. Just run `go build ./cmd/payment/` in project directory.
+
+## Running
+Configuration is done via environment variables. These are the list of environment variables that the program supports:
+
+* `DATABASE_URL`: The URL used to connect to PostgreSQL database. For example: `host=localhost user=gorm password=gorm dbname=gorm port=9920`. [Read More](https://gorm.io/docs/connecting_to_the_database.html#PostgreSQL)
+* `LISTEN_ADDRESS`: On what address should we listen? For example `127.0.0.1:12345`
+* `IDPAY_APIKEY`: The API token of IDPay.
+* `IDPAY_SANDBOX`: Should we run IDPay in sandbox environment for testing? This value should be a boolean and defaults to false.
+* `GIN_MODE`: Set this value to `release` in production.
+
+After setting these variables, just run the compiled program.