perf: minify app shell

[jeffbcross]

The html output of app shell has lots of unneeded whitespace. My quick experiment of minifying via a web-based html minifier then gzipping it yielded an improvement of about 800 bytes over unminified gzipped:

• 20432 bytes unminified.html
• 3322 bytes unminified.html.gz
• 12262 bytes minified.html
• 2520 bytes minified.html.gz

3322-2520 = 802 bytes saved