Use winston for logging

src/util.ts

@@ -1,10 +1,11 @@
 import PhoneNumber from "awesome-phonenumber";
-import winston from "winston";
+import winston, { format } from "winston";
 
 export const DEBUG = !!process.env.DEBUG;
 export const logger = winston.createLogger({
   level: DEBUG ? "debug" : process.env.LOG_LEVEL ?? "info",
   transports: [new winston.transports.Console()],
+  format: format.printf(({ level, message }) => `${level}: ${message}`),
 });
 
 export function getNationalNumber(input: string) {