Add micros clock

src/espchrono.h

@@ -135,6 +135,18 @@ struct millis_clock
   static time_point now() noexcept;
 };
 
+struct micros_clock
+{
+    typedef std::chrono::microseconds 	duration;
+    typedef duration::rep	  				rep;
+    typedef duration::period	  			period;
+    typedef std::chrono::time_point<micros_clock, duration> 	time_point;
+
+    static constexpr bool is_steady = true;
+
+    static time_point now() noexcept;
+};
+
 struct DateTime
 {
     date::year_month_day date;

src/espchrono_impl.cpp

@@ -24,3 +24,8 @@ auto espchrono::millis_clock::now() noexcept -> time_point
 {
     return time_point{std::chrono::floor<duration>(std::chrono::microseconds{esp_timer_get_time()})};
 }
+
+auto espchrono::micros_clock::now() noexcept -> time_point
+{
+    return time_point{std::chrono::microseconds{esp_timer_get_time()}};
+}