Intial somewhat working version

src/FileUtil.cpp

@@ -0,0 +1,29 @@
+#include "FileUtil.h"
+
+#include <fstream>
+#include <sstream>
+
+std::optional<std::string> readTextFile(const std::filesystem::path& path)
+{
+    std::ifstream file(path, std::ios::binary);
+    if (!file)
+        return std::nullopt;
+
+    std::ostringstream buffer;
+    buffer << file.rdbuf();
+    return buffer.str();
+}
+
+std::string contentTypeForPath(const std::filesystem::path& path)
+{
+    const auto ext = path.extension().string();
+    if (ext == ".html")
+        return "text/html; charset=utf-8";
+    if (ext == ".css")
+        return "text/css; charset=utf-8";
+    if (ext == ".js")
+        return "application/javascript; charset=utf-8";
+    if (ext == ".json")
+        return "application/json; charset=utf-8";
+    return "application/octet-stream";
+}