Add content to advanced go (#6477)

* Add advance Go intro

I've added an introduction to Go advance and included the relevant links

* Update src/data/roadmaps/golang/content/101-go-advanced/index.md

* Update src/data/roadmaps/golang/content/101-go-advanced/index.md

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Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

src/data/roadmaps/golang/content/101-go-advanced/index.md

@@ -1 +1,7 @@
 # Go advanced
+
+Diving deeper into Golang involves exploring the language's more advanced features and best practices to harness its full potential. Once you’ve mastered the basics, advancing your knowledge includes understanding complex aspects of Go that can significantly improve your code’s performance, readability, and maintainability.
+
+Visit the following resources to learn more:
+
+- [@article@Mastering Advance GO](https://www.reddit.com/r/golang/comments/m57vwe/advanced_go_techniques_you_think_everyone_should/)