Create build system (#1)

src/mime_types.rs

@@ -0,0 +1,20 @@
+macro_rules! mimes {
+($($ident: ident = $value: literal),*$(,)?) => {
+    pub enum MimeType {
+        $($ident),*
+    }
+
+    impl MimeType {
+        pub fn text(&self) -> &'static str {
+            match self { $(Self::$ident => $value),* }
+        }
+    }
+};
+}
+
+mimes! {
+    Txt = "text/plain",
+    Html = "text/html",
+    Css = "text/css",
+    Js = "text/javascript",
+}