docs: Add guide for measuring execution time in C++

Author: LuchoBazz

website/docs/c-cpp/measuring-execution-time.md

@@ -0,0 +1,43 @@
+---
+sidebar_position: 3
+title: Measuring Execution Time in C++
+sidebar_label: Measuring Execution Time in C++
+---
+
+## Measuring Execution Time in C++
+
+This simple example shows how to measure the execution time of a block of code using the `<chrono>` library.
+
+### Code Example
+
+```cpp
+// #include <chrono>
+
+auto start = chrono::high_resolution_clock::now();
+
+// CODE TO BE MEASURED
+// Example: for (int i = 0; i < 1000000; ++i) {}
+
+auto end = chrono::high_resolution_clock::now();
+
+chrono::duration<double, milli> duration = end - start;
+cout << "Execution time: " << duration.count() << " ms" << endl;
+```
+
+### Explanation
+
+* `chrono::high_resolution_clock::now()`
+  Captures the current high-precision timestamp (start and end).
+
+* `end - start`
+  Calculates the elapsed time between the two timestamps.
+
+* `chrono::duration<double, milli>`
+  Converts the time difference into **milliseconds**.
+
+* `duration.count()`
+  Returns the numerical value of the elapsed time, which is printed to the console.
+
+### Tip
+
+You can replace the comment `// CODE TO BE MEASURED` with any operation you want to benchmark — for example, loops, function calls, or algorithm executions.