Add About component and update styles

src/App.tsx

@@ -1,12 +1,14 @@
 import "@styles/App.scss";
 import Header from "@components/Header";
+import About from "@components/About";
 
 export default function App() {
 	return (
 		<div id="app">
 			<Header />
+			<About />
 			<div style={{ textAlign: "center" }}>
-				<h1>Website under construction 🚧👷</h1>
+				<h4>Website under construction 🚧👷</h4>
 			</div>
 		</div>
 	);