feat: add deprecation message (#320)

Author: radko93

Diff for: README.md

@@ -1,4 +1,8 @@
-# :space_invader: React Native Template TypeScript
+# This template is deprecated
+
+React Native added [first-class support for Typescript in version 0.71](https://reactnative.dev/blog/2023/01/03/typescript-first), with the base template now utilizing it. Additionally, the types have been integrated into the React Native repository. Although this template can still be used to generate projects with older versions of React Native, we will no longer update it. We would like to express our gratitude to all contributors for their efforts in enhancing this template over the years.
+
+## :space_invader: React Native Template TypeScript
 
 <p>
   <a href="https://github.com/react-native-community/react-native-template-typescript/actions/workflows/npm-publish.yml">
@@ -26,15 +30,7 @@
 ## :arrow_forward: Usage
 
 ```sh
-npx react-native init MyApp --template react-native-template-typescript
-```
-
-### Usage with older versions of React Native
-
-#### e.g. `[email protected]`
-
-```sh
-npx react-native init MyApp --template [email protected]
+npx react-native init MyApp --template [email protected]
 ```
 
 See the below table to find out which version of the template to use.