add QCodeEditor

external/QCodeEditor/example/resources/code_samples/cxx.cpp

@@ -0,0 +1,17 @@
+#include <iostream>
+
+int main()
+{
+    int n, sum = 0;
+
+    std::cout << "Enter a positive integer: ";
+    std::cin >> n;
+
+    for (int i = 1; i <= n; ++i)
+    {
+        sum += i;
+    }
+
+    std::cout << "Sum = " << sum;
+    return 0;
+}