Apply suggestions from code review

Author: benjie

src/pages/learn/schema-design.mdx

@@ -4,11 +4,11 @@
 
 ## Versioning
 
-While there's nothing that prevents a GraphQL service from being versioned just like any other REST API, GraphQL takes a strong opinion on avoiding versioning by providing the tools for the continuous evolution of a GraphQL schema.
+While there's nothing that prevents a GraphQL service from being versioned just like any other API, GraphQL takes a strong opinion on avoiding versioning by providing the tools for the continuous evolution of a GraphQL schema.
 
 Why do most APIs version? When there's limited control over the data that's returned from an API endpoint, _any change_ can be considered a breaking change, and breaking changes require a new version. If adding new features to an API requires a new version, then a tradeoff emerges between releasing often and having many incremental versions versus the understandability and maintainability of the API.
 
-In contrast, GraphQL only returns the data that's explicitly requested, so new capabilities can be added via new types and new fields on those types without creating a breaking change. This has led to a common practice of always avoiding breaking changes and serving a versionless API.
+In contrast, GraphQL only returns the data that's explicitly requested, so new capabilities can be added via new types or new fields on existing types without creating a breaking change. This has led to a common practice of always avoiding breaking changes and serving a versionless API.
 
 ## Nullability