docs: update Resources section

Author: Abanoub-Asaad

README.md

@@ -3,6 +3,12 @@
 In this repository, you will find :
   - [A roadmap for learning Backend with Java](#roadmap)
   - [Resources for learning Java-Backend](#resources-for-learning-java-backend)
+    - [Docs & Articles](https://github.com/Abanoub-Asaad/Java-Backend#docs--articles)
+    - [YouTube Channels](https://github.com/Abanoub-Asaad/Java-Backend#youtube-channels)
+    - [Books](https://github.com/Abanoub-Asaad/Java-Backend#books)
+    - [Projects](https://github.com/Abanoub-Asaad/Java-Backend#projects)
+    - [Helpful Links](https://github.com/Abanoub-Asaad/Java-Backend#helpful-links)
+    - [Interview Questions](https://github.com/Abanoub-Asaad/Java-Backend#interview-questions)
   - [References of the roadmap](#references-of-the-roadmap)
   - [Want to contribute to this repository?](#contribution)