Update provider-scopes.md

Author: kamilmysliwiec

content/fundamentals/provider-scopes.md

@@ -2,7 +2,7 @@
 
 For people coming from different programming language backgrounds, it might be unexpected to learn that in Nest, almost everything is shared across incoming requests. We have a connection pool to the database, singleton services with global state, etc. Remember that Node.js doesn't follow the request/response Multi-Threaded Stateless Model in which every request is processed by a separate thread. Hence, using singleton instances is fully **safe** for our applications.
 
-However, there are edge-cases when request-based lifetime may be the desired behavior, for instance per-request caching in GraphQL applications, request tracking, and multi-tenancy. Injection scopes provide a mechanism to obtain the desired provider lifetime behavior.
+However, there are edge cases when request-based lifetime may be the desired behavior, for instance, per-request caching in GraphQL applications, request tracking, and multi-tenancy. Injection scopes provide a mechanism to obtain the desired provider lifetime behavior.
 
 #### Provider scope
 
@@ -151,7 +151,7 @@ Using request-scoped providers will have an impact on application performance. W
 
 #### Durable providers
 
-Request-scoped providers, as mentioned in the section above, may lead to increased latency since having at least 1 request-scoped provider (injected into the controller instance, or deeper - injected into one of its providers) makes the controller request-scoped as well. That means, it must be recreated (instantiated) per each individual request (and garbage collected afterwards). Now, that also means, that for let's say 30k requests in parallel, there will be 30k ephemeral instances of the controller (and its request-scoped providers).
+Request-scoped providers, as mentioned in the section above, may lead to increased latency since having at least 1 request-scoped provider (injected into the controller instance, or deeper - injected into one of its providers) makes the controller request-scoped as well. That means it must be recreated (instantiated) per each individual request (and garbage collected afterward). Now, that also means, that for let's say 30k requests in parallel, there will be 30k ephemeral instances of the controller (and its request-scoped providers).
 
 Having a common provider that most providers depend on (think of a database connection, or a logger service), automatically converts all those providers to request-scoped providers as well. This can pose a challenge in **multi-tenant applications**, especially for those that have a central request-scoped "data source" provider that grabs headers/token from the request object and based on its values, retrieves the corresponding database connection/schema (specific to that tenant).
 
@@ -207,7 +207,7 @@ return {
   resolve: (info: HostComponentInfo) =>
     info.isTreeDurable ? tenantSubTreeId : contextId,
   payload: { tenantId },
-  }
+}
 ```
 
 Now whenever you inject the `REQUEST` provider (or `CONTEXT` for GraphQL applications) using the `@Inject(REQUEST)`/`@Inject(CONTEXT)`, the `payload` object would be injected (consisting of a single property - `tenantId` in this case).