Apply suggestions from code review

Author: jasonkuhrt

src/utils.ts

@@ -601,8 +601,9 @@ export function graphql15InterfaceType<T extends GraphQLInterfaceType>(
   return type as T & { getInterfaces(): GraphQLInterfaceType[] }
 }
 
-// A function that is correctly typed to get arround a TypeScript issue.
-// See https://github.com/microsoft/TypeScript/issues/17002
+/**
+ * A specially typed version of `Array.isArray` to work around [this issue](https://github.com/microsoft/TypeScript/issues/17002).
+ */
 export function isArray<T>(
   arg: T | {}
 ): arg is T extends readonly any[] ? (unknown extends T ? never : readonly any[]) : any[] {