Updated README

include/builder/i_file_builder.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <fstream>
+#include <string>
+
+namespace builder {
+    class IFileBuilder {
+    public:
+        virtual ~IFileBuilder() noexcept = default;
+        virtual std::string get_extension() noexcept = 0;
+        virtual void write_top_level(std::ofstream& output) noexcept = 0;
+        virtual void write_namespace(std::ofstream& output, const std::string& namespace_name) noexcept = 0;
+        virtual void write_variable(std::ofstream& output, const std::string& variable_name, std::uint64_t variable_value) noexcept = 0;
+        virtual void write_closure(std::ofstream& output, bool eof) noexcept = 0;
+    };
+}