Update pyramid example

Author: dxrcy

example/pyramid.cpp

@@ -34,8 +34,7 @@ int main() {
     int min_height = *std::min_element(heights.begin(), heights.end());
 
     // Build rings, diminishing up to pyramid height
-    mcpp::Coordinate base_pt = heights.base_pt();
-    base_pt.y = min_height;
+    mcpp::Coordinate base_pt = {heights.base_pt(), min_height};
     int side_len = pyramid_base_len;
     for (int i = 0; i < PYRAMID_HEIGHT; i++) {
         make_ring(base_pt + mcpp::Coordinate(i, i, i), side_len - (i * 2));