chore: add resource under cpp:basic-operations:loops

src/data/roadmaps/cpp/content/102-basic-operations/102-loops.md

@@ -85,3 +85,5 @@ int main() {
 ```
 
 In summary, loops are an integral part of C++ programming that allow you to execute a block of code multiple times. The three types of loops in C++ are `for`, `while`, and `do-while`. Each type has its own specific use case and can be chosen depending on the desired behavior.
+
+- [C++ For Loop](https://www.w3schools.com/cpp/cpp_for_loop.asp)