docs: update open points in readme

Author: MrWolfZ

README.md

@@ -81,7 +81,6 @@ This library was heavily inspired by [Rematch](https://rematch.gitbooks.io/remat
 - core: throw when calling mutation from inside another mutation (i.e. nested dispatch)
 - core: add memoization to selectors (also mention this briefly in the "derived state" recipe)
 - core: add note to "composing my selectors" recipe about interplay with memoization (e.g. due to in-place sorting)
-- core: add function to create effect (module-agnostic) to allow mocking them
 - react: add tests that verify HMR works
 - react: add tests that verify server-side rendering works
 - react: verify package works with react-native