fix(guide): simplify directory structure

guide/english/cplusplus/range-for-loop/index.md

@@ -0,0 +1,29 @@
+---
+title: Range For Loop
+---
+
+## Range-based for loop
+
+The ranged-based `for` loop allows easy looping over a range of elements (like elements in a container).
+
+With traditional `for` loop:
+
+```cpp
+std::vector<std::string> stringList {"one", "two", "three"};
+
+for (size_t il; il < stringList.size(); il++
+{
+  std::cout << stringList.at(il) << std::endl;
+}
+```
+
+With range-based `for` loop:
+
+```cpp
+std::vector<std::string> stringList {"one", "two", "three"};
+
+for (auto& singleString : stringList)
+{
+  std:cout << singleString << std::endl;
+}
+```