Added user login & registration. Added SQL file for postgres database.

backend/nestjs-seshat-api/src/app.controller.ts

@@ -0,0 +1,13 @@
+import { Controller, Get } from '@nestjs/common';
+import { AppService } from './app.service';
+import { UsersService } from './users/users.service';
+
+@Controller()
+export class AppController {
+  constructor(private readonly appService: AppService, private readonly users: UsersService) {}
+
+  @Get()
+  async getHello(): Promise<string> {
+    return this.appService.getHello();
+  }
+}