Given some [confusion around `react-native bundle`'s `--dev` flag][1],
this hopes to clear somet things up int he docs by…
- Removing mentions of the `__DEV__` environment variable
- I think it confuses the user on how to work with the command-line
flag, and frankly it seems like an internal implementation detail
from the perspective of react-native-cli. We should focus on what
the `--dev` flag does (e.g., toggles dev warnings, performance
optimizations).
- Adding a minimal note about native-land's build configurations and how
that should be checked for production builds
[1]: https://github.com/facebook/react-native/issues/4181
d92b3b3e9b