docs: update comparison (#103)

Adds "declarative" as an option for API definition for React Query. With v3, you can now configure all of your queries and mutations up front before calling them.

Author: tannerlinsley

docs/introduction/comparison.md

@@ -21,7 +21,7 @@ This comparison table strives to be as accurate and as unbiased as possible. If
 | Feature                                | rtk-query                               | react-query              | apollo                                                                              | urql                                                                                                        |
 | -------------------------------------- | --------------------------------------- | ------------------------ | ----------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------- |
 | **Supported Protocols**                | any, REST included                      | any, none included       | GraphQL                                                                             | GraphQL                                                                                                     |
-| **API Definition**                     | declarative                             | on use                   | GraphQL schema                                                                      | GraphQL schema                                                                                              |
+| **API Definition**                     | declarative                             | on use, declarative      | GraphQL schema                                                                      | GraphQL schema                                                                                              |
 | **Cache by**                           | endpoint + serialized arguments         | user-defined query-key   | type/id                                                                             | type/id?                                                                                                    |
 | **Invalidation Strategy + Refetching** | declarative, by type and/or type/id     | manual by cache key      | automatic cache updates on per-entity level, manual query invalidation by cache key | declarative, by type OR automatic cache updates on per-entity level, manual query invalidation by cache key |
 | **Polling **                           | yes                                     | yes                      | yes                                                                                 | yes                                                                                                         |