feat(P0-001): scaffold monorepo structure (#60)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/gateway/src/app.module.ts

@@ -0,0 +1,7 @@
+import { Module } from '@nestjs/common';
+import { HealthController } from './health/health.controller.js';
+
+@Module({
+  controllers: [HealthController],
+})
+export class AppModule {}