Fix links to beginner friendly issues

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While I was reading README I found wrong links to `beginner friendly issues` so just fixed them.
Closes #17579

Differential Revision: D6719845

Pulled By: shergin

fbshipit-source-id: 5c3290f70efbd8c40c2d3482c23c198ab45d510e

CONTRIBUTING.md

@@ -78,7 +78,7 @@ Working on your first Pull Request? You can learn how from this free video serie
 
 [**How to Contribute to an Open Source Project on GitHub**](https://egghead.io/courses/how-to-contribute-to-an-open-source-project-on-github)
 
-We have a list of [beginner friendly issues](https://github.com/facebook/react-native/labels/Good%20First%20Task) to help you get your feet wet in the React Native codebase and familiar with our contribution process. This is a great place to get started.
+We have a list of [beginner friendly issues](https://github.com/facebook/react-native/labels/Good%20first%20issue) to help you get your feet wet in the React Native codebase and familiar with our contribution process. This is a great place to get started.
 
 ### Proposing a change
 

README.md

@@ -66,7 +66,7 @@ Read our [contributing guide](https://facebook.github.io/react-native/docs/contr
 
 ### Beginner Friendly Bugs
 
-We have a list of [beginner friendly issues](https://github.com/facebook/react-native/labels/Good%20First%20Issue) to help you get your feet wet in the React Native codebase and familiar with our contribution process. This is a great place to get started.
+We have a list of [beginner friendly issues](https://github.com/facebook/react-native/labels/Good%20first%20issue) to help you get your feet wet in the React Native codebase and familiar with our contribution process. This is a great place to get started.
 
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