refactor: Add missing route to OPENAPI_ROUTES (#769)

Author: d4mr

src/server/middleware/open-api.ts

@@ -1,7 +1,7 @@
 import swagger from "@fastify/swagger";
 import type { FastifyInstance } from "fastify";
 
-export const OPENAPI_ROUTES = ["/json", "/openapi.json"];
+export const OPENAPI_ROUTES = ["/json", "/openapi.json", "/json/"];
 
 export const withOpenApi = async (server: FastifyInstance) => {
   await server.register(swagger, {