feat: introducing rate-limiting on queries, mutations and most of the REST endpoints (HBE-111) (#46)

* feat: rate-limiting guard added and configured in app module

* feat: rate-limit annotation added in controllers and resolvers (query, mutation, not subscription)

* docs: added comments

packages/hoppscotch-backend/src/app.module.ts

@@ -18,6 +18,7 @@ import { AdminModule } from './admin/admin.module';
 import { UserCollectionModule } from './user-collection/user-collection.module';
 import { ShortcodeModule } from './shortcode/shortcode.module';
 import { COOKIES_NOT_FOUND } from './errors';
+import { ThrottlerModule } from '@nestjs/throttler';
 
 @Module({
   imports: [
@@ -60,6 +61,10 @@ import { COOKIES_NOT_FOUND } from './errors';
       }),
       driver: ApolloDriver,
     }),
+    ThrottlerModule.forRoot({
+      ttl: +process.env.RATE_LIMIT_TTL,
+      limit: +process.env.RATE_LIMIT_MAX,
+    }),
     UserModule,
     AuthModule,
     AdminModule,