Fixed a typo in README for better clarity and understanding (facebook#47918)

Summary:
I was just going through the README file, and I felt that the word "repo" seems a bit informal. Thus I made the correction and made it "repository".

## Changelog:

[General] [Changed] - Fixed a typo in the README file.

Pull Request resolved: facebook#47918

Test Plan: No specific Test Plan for these changes, as it is just a typo fix in README.md

Reviewed By: fkgozali

Differential Revision: D66414686

Pulled By: arushikesarwani94

fbshipit-source-id: 578530d2dcdf046a90bf5a5bc32ba68e8f496c81

Author: Aryan2727-debug

README.md

@@ -87,7 +87,7 @@ The full documentation for React Native can be found on our [website][docs].
 
 The React Native documentation discusses components, APIs, and topics that are specific to React Native. For further documentation on the React API that is shared between React Native and React DOM, refer to the [React documentation][r-docs].
 
-The source for the React Native documentation and website is hosted on a separate repo, [**@facebook/react-native-website**][repo-website].
+The source for the React Native documentation and website is hosted on a separate repository, [**@facebook/react-native-website**][repo-website].
 
 [docs]: https://reactnative.dev/docs/getting-started
 [r-docs]: https://react.dev/learn