Updated Implementing Power Save, aka Idling outside of ImGui (markdown)

Implementing-Power-Save,-aka-Idling-outside-of-ImGui.md

@@ -126,7 +126,7 @@ bool ShallIdleThisFrame_Emscripten(FpsIdling& ioIdling)
     }
 
     static double lastRefreshTime = 0.;
-    double now = Internal::ClockSeconds();
+    double now = ClockSeconds();
 
     bool shallIdleThisFrame = false;
     if (hasInputEvent)
@@ -150,4 +150,17 @@ bool ShallIdleThisFrame_Emscripten(FpsIdling& ioIdling)
 }
 ```
 
+where ClockSeconds could be implemented for example like this:
 
+```cpp
+#include <chrono>
+
+double ClockSeconds() 
+{
+    static const auto start = std::chrono::steady_clock::now();
+    auto now = std::chrono::steady_clock::now();
+    std::chrono::duration<double> elapsed = now - start;
+    return elapsed.count();
+}
+
+```