The error message wasn't very helpful. I didn't understand the problem
until I debugged the `RCTJavaScriptLoader`. So this might be to help for
others.
Squashed commits by @andrewsardone into @hfossli’s [original
commit][oc]:
[oc]: 39fa5ca95b
- Expand App Transport Security docs w/ localhost tip
- Tweak ATS error note in EmbeddedAppIOS docs
- Per @satya164’s [recommendation][r], using the exact copy he
recommended.
[r]: https://github.com/facebook/react-native/pull/5290#discussion_r49843876
These instructions were already in the docs; just gave them more meat and deleted the old instructions that talked about installing from the Pod repo. Now, we publish only to npm so these instructions are important.