Update custom app example in README

[borekb]

The code example now uses simpler and "safer" approach to call page's getInitialProps.

Pros:

• Shorter code.
• Probably more resilient / reliable as it goes through loadGetInitialProps that handles quite a few details.
• I've seen the approach with const appProps = await App.getInitialProps(appContext) in several examples and blog posts (didn't take notes though..).

Cons:

• It was less intuitive to me, initially, that this indeed calls page's getInitialProps.

[ijjk]

Stats from current PR

Click to expand stats

	zeit/next.js canary	borekb/next.js patch-1	Change
Build Duration	22.7s	22.5s	-251ms
node_modules Size	41.6 MB	41.6 MB	-1 B
Total Bundle (main, webpack, commons) Size	214 kB	214 kB	✓
Total Bundle (main, webpack, commons) gzip Size	70.6 kB	70.6 kB	-1 B
Total Bundle (main, webpack, commons) Modern Size	189 kB	189 kB	✓
Total Bundle (main, webpack, commons) Modern gzip Size	62.4 kB	62.4 kB	✓
Client _app Size	2.39 kB	2.39 kB	✓
Client _app gzip Size	1.08 kB	1.08 kB	-1 B
Client _app Modern Size	1.83 kB	1.83 kB	✓
Client _app gzip Modern Size	890 B	890 B	✓
Client _error Size	8.22 kB	8.22 kB	✓
Client _error gzip Size	3.16 kB	3.16 kB	✓
Client _error Modern Size	5.85 kB	5.85 kB	✓
Client _error gzip Modern Size	2.33 kB	2.33 kB	✓
Client pages/index Size	343 B	343 B	✓
Client pages/index gzip Size	246 B	246 B	✓
Client pages/index Modern Size	319 B	319 B	✓
Client pages/index gzip Modern Size	254 B	254 B	✓
Client pages/link Size	4.18 kB	4.18 kB	✓
Client pages/link gzip Size	1.82 kB	1.82 kB	✓
Client pages/link Modern Size	3.81 kB	3.81 kB	✓
Client pages/link gzip Modern Size	1.72 kB	1.72 kB	-1 B
Client pages/routerDirect Size	423 B	423 B	✓
Client pages/routerDirect gzip Size	306 B	306 B	✓
Client pages/routerDirect Modern Size	411 B	411 B	✓
Client pages/routerDirect gzip Modern Size	314 B	314 B	✓
Client pages/withRouter Size	435 B	435 B	✓
Client pages/withRouter gzip Size	301 B	300 B	-1 B
Client pages/withRouter Modern Size	423 B	423 B	✓
Client pages/withRouter gzip Modern Size	309 B	309 B	✓
Client main Size	16.3 kB	16.3 kB	✓
Client main gzip Size	5.73 kB	5.73 kB	✓
Client main Modern Size	13.1 kB	13.1 kB	✓
Client main Modern gzip Size	4.99 kB	4.99 kB	✓
Client commons Size	195 kB	195 kB	✓
Client commons gzip Size	63.6 kB	63.6 kB	✓
Client commons Modern Size	176 kB	176 kB	✓
Client commons Modern gzip Size	57.4 kB	57.4 kB	✓
Client webpack Size	1.53 kB	1.53 kB	✓
Client webpack gzip Size	778 B	778 B	✓
Client webpack Modern Size	1.53 kB	1.53 kB	✓
Client webpack Modern gzip Size	785 B	785 B	✓
Base Rendered Size	2.76 kB	2.76 kB	✓
Build Dir Size	1.44 MB	1.44 MB	✓

Click to expand serverless stats

	zeit/next.js canary	borekb/next.js patch-1	Change
Build Duration	25.1s	25s	-44ms
node_modules Size	41.6 MB	41.6 MB	-1 B
Total Bundle (main, webpack, commons) Size	214 kB	214 kB	✓
Total Bundle (main, webpack, commons) gzip Size	70.6 kB	70.6 kB	✓
Total Bundle (main, webpack, commons) Modern Size	189 kB	189 kB	✓
Total Bundle (main, webpack, commons) Modern gzip Size	62.4 kB	62.4 kB	✓
Client _app Size	2.39 kB	2.39 kB	✓
Client _app gzip Size	1.08 kB	1.08 kB	✓
Client _app Modern Size	1.83 kB	1.83 kB	✓
Client _app gzip Modern Size	890 B	890 B	✓
Client _error Size	8.22 kB	8.22 kB	✓
Client _error gzip Size	3.16 kB	3.16 kB	✓
Client _error Modern Size	5.85 kB	5.85 kB	✓
Client _error gzip Modern Size	2.33 kB	2.33 kB	✓
Client pages/index Size	343 B	343 B	✓
Client pages/index gzip Size	246 B	246 B	✓
Client pages/index Modern Size	319 B	319 B	✓
Client pages/index gzip Modern Size	254 B	254 B	✓
Client pages/link Size	4.18 kB	4.18 kB	✓
Client pages/link gzip Size	1.82 kB	1.82 kB	✓
Client pages/link Modern Size	3.81 kB	3.81 kB	✓
Client pages/link gzip Modern Size	1.72 kB	1.72 kB	✓
Client pages/routerDirect Size	423 B	423 B	✓
Client pages/routerDirect gzip Size	306 B	306 B	✓
Client pages/routerDirect Modern Size	411 B	411 B	✓
Client pages/routerDirect gzip Modern Size	314 B	314 B	✓
Client pages/withRouter Size	435 B	435 B	✓
Client pages/withRouter gzip Size	301 B	301 B	✓
Client pages/withRouter Modern Size	423 B	423 B	✓
Client pages/withRouter gzip Modern Size	309 B	309 B	✓
Client main Size	16.3 kB	16.3 kB	✓
Client main gzip Size	5.73 kB	5.73 kB	✓
Client main Modern Size	13.1 kB	13.1 kB	✓
Client main Modern gzip Size	4.99 kB	4.99 kB	✓
Client commons Size	195 kB	195 kB	✓
Client commons gzip Size	63.6 kB	63.6 kB	✓
Client commons Modern Size	176 kB	176 kB	✓
Client commons Modern gzip Size	57.4 kB	57.4 kB	✓
Client webpack Size	1.53 kB	1.53 kB	✓
Client webpack gzip Size	778 B	778 B	✓
Client webpack Modern Size	1.53 kB	1.53 kB	✓
Client webpack Modern gzip Size	785 B	785 B	✓
Serverless pages/link Size	256 kB	256 kB	✓
Serverless pages/link gzip Size	68.8 kB	68.8 kB	✓
Serverless pages/index Size	249 kB	249 kB	✓
Serverless pages/index gzip Size	66.6 kB	66.6 kB	✓
Serverless pages/_error Size	248 kB	248 kB	✓
Serverless pages/_error gzip Size	66.3 kB	66.3 kB	✓
Serverless pages/routerDirect Size	249 kB	249 kB	✓
Serverless pages/routerDirect gzip Size	66.5 kB	66.5 kB	✓
Serverless pages/withRouter Size	249 kB	249 kB	✓
Serverless pages/withRouter gzip Size	66.6 kB	66.6 kB	✓
Build Dir Size	2.65 MB	2.65 MB	✓

[timneutkens]

Thanks!