Set up PostgreSQL database configuration and enhance application structure

- Added .env.example with database connection details and JWT configuration.
- Introduced docker-compose.yml for PostgreSQL service setup with health checks.
- Created drizzle.config.ts for database schema and migration management.
- Updated nest-cli.json to include Swagger plugin configuration for API documentation.
- Enhanced package.json with new database-related scripts and dependencies.
- Implemented initial database migrations for user and token management.
- Configured application bootstrap process to load environment variables and set up Swagger.
- Added shared application configuration in configure-app.ts for consistent setup.
- Included unit tests for application configuration and Swagger setup.

nest-cli.json

@@ -3,6 +3,16 @@
   "collection": "@nestjs/schematics",
   "sourceRoot": "src",
   "compilerOptions": {
-    "deleteOutDir": true
+    "deleteOutDir": true,
+    "plugins": [
+      {
+        "name": "@nestjs/swagger",
+        "options": {
+          "classValidatorShim": true,
+          "introspectComments": true,
+          "dtoFileNameSuffix": [".dto.ts"]
+        }
+      }
+    ]
   }
 }