Add svg.cpp

Histogram/svg.cpp

@@ -1 +1,18 @@
+#include "svg.h"
+#include <iostream>
 
+void svg_begin(double width, double height) {
+    std::cout << "<?xml version='1.0' encoding='UTF-8'?>\n";
+    std::cout << "<svg ";
+    std::cout << "width='" << width << "' ";
+    std::cout << "height='" << height << "' ";
+    std::cout << "viewBox='0 0 " << width << " " << height << "' ";
+    std::cout << "xmlns='http://www.w3.org/2000/svg'>\n";
+}
+
+void svg_end() {
+    std::cout << "</svg>\n";
+}
+
+void svg_rect(double x, double y, double width, double height, std::string stroke, std::string fill) {
+    std::cout << "<rect x='" << x << "' y='" << y << "' width='" << width << "' height='" << height << "' stroke