Integrate google analytics

pages/_app.tsx

@@ -1,9 +1,15 @@
+import { useEffect } from 'react';
 import type { AppProps } from 'next/app';
 import { ChakraProvider } from '@chakra-ui/react';
-import { roadmapTheme } from '../lib/theme';
 import 'prism-themes/themes/prism-shades-of-purple.css';
+import { roadmapTheme } from '../lib/theme';
+import { firePageView } from '../lib/gtag';
 
 function MyApp({ Component, pageProps }: AppProps) {
+  useEffect(() => {
+    firePageView(window.location.pathname);
+  }, []);
+
   return (
     <ChakraProvider theme={roadmapTheme}>
       <Component {...pageProps} />