docs(jest-native): add deprecation message

Author: gbhasha

docs/ecosystem-jest-native.mdx

@@ -30,6 +30,14 @@ expect(queryByTestId('not-empty')).not.toBeEmpty()
 > `getByTestId`). Otherwise the `get*` function could throw an error before your
 > assertion.
 
+> [!CAUTION]
+> **This package is deprecated and is no longer actively maintained.**
+> 
+> We encourage you to migrate to React Native Testing Library, v12.4 or later, which includes modern [built-in Jest matchers](https://callstack.github.io/react-native-testing-library/docs/api/jest-matchers) based on the matchers for this repository.
+>
+> The migration process should be relatively straightforward, we have a [migration guide](https://callstack.github.io/react-native-testing-library/docs/migration/jest-matchers) available.
+
+
 Check out
 [Jest Native's documentation](https://github.com/testing-library/jest-native)
 for a full list of available matchers.