Add dark theme;

All components are styled: input, select, checkbox, range;
Improved minor stylistic details;
SVG import reworked

Author: IvanSavoskin

custom_typing/svg.d.ts

@@ -1,4 +1,6 @@
 declare module "*.svg" {
-    const content: string;
+    import React from "react";
+
+    const content: React.FunctionComponent<React.SVGProps<SVGSVGElement>>;
     export default content;
 }