add Chapter01 examples

Chapter01/compile_time_const.cpp

@@ -0,0 +1,10 @@
+#include <cstdio>
+
+constexpr float voltage = 3300;
+constexpr float current = 1000;
+
+int main() {
+  const float resistance = voltage / current;
+  printf("resistance = %.2f\r\n", resistance);
+  return 0;
+}