Readme: Mention somewhere that panic overlay only auto-shows if Devtools closed

[malcolmocean]

I was really confused because calling panic(new Error("what")) in DevTools would show it, but then if I just tried to throw an error, or introduce an error into my code on purpose, it would just show in the console. But then it worked as expected when I closed DevTools. You may want to mention this!

[xpl]

LOL I wasn't even aware of that! Thanks for the heads up. Do you have any idea why that could possibly happen, btw?

[malcolmocean]

Haha no I don't know. The only way I'm even aware of testing for whether devtools is open is really weird...

var devtools = /./
devtools.toString = function() {
  this.opened = true
}
console.log('%c', devtools)

then devtools.opened will be set to true iff devtools has been opened since the page was loaded. (I think even if now closed)

Although in your case you can actually call in the console:

setTimeout(() => document.body.appendChild(666), 2000)

then close devtools and wait 2s and it'll panic appropriately.