feat: add info about figma and sketch to the readme (#1988)

Author: Trancever

README.md

@@ -44,6 +44,10 @@ Check the components and their usage in our [documentation](https://callstack.gi
 
 Read the [contribution guidelines](/CONTRIBUTING.md) before contributing.
 
+## Figma and Sketch component kits
+
+Use official component kits provided by [Material Design](https://material.io/resources). 
+
 ## Made with ❤️ at Callstack
 
 `react-native-paper` is an open source project and will always remain free to use. If you think it's cool, please star it 🌟. [Callstack][callstack-readme-with-love] is a group of React and React Native geeks, contact us at [hello@callstack.com](mailto:hello@callstack.com) if you need any help with these or just want to say hi!