Add Button component

src/cryptometrics/components/button/Button.js

+import classNames from "classnames";
+import React from "react";
+
+export default function Button({ children, className, onClick }) {
+  return (
+    <button
+      className={classNames("py-2 px-5 rounded-xl", className)}
+      onClick={onClick}
+    >
+      {children}
+    </button>
+  );
+}