Introduce Gemfile, ruby-version and nvmrc to template

[barbieri]

The template/ios uses Podfile and that is based on Ruby and CocoaPods.

To aid the process we could provide a Gemfile and associated Gemfile.lock with the recommended ruby and CocoaPods version, this way we avoid issues such as using the incorrect versions. Then we change every reference to Execute pod install to be Execute bundle exec pod install to make sure the correct versions are used.

By providing a .ruby-version file, we could help http://rbenv.org/ and https://rvm.io/ uses to use the correct version and avoid pitfalls (such as using the default macOS version, that is a universal binary and may cause issues with ffi on arm64/m1).

Along these lines, we could also provide .nvmrc with the tested/recommended version and even lock package.json with engines: { node: "..." }, this way we minimize problems.

I also reported it to react-native-community/react-native-template-typescript#225, but it was said that this change should go in React-Native itself and then they will adapt in future releases.

[kelset]

This sounds reasonable - would you mind making directly a PR so that it can be discussed "code in hands"?

[barbieri]

will do!

[barbieri]

First attempt at facebook/react-native#32303

[Adnan-Bacic]

i like the idea of having the version of Node in the project too with an .nvmrc file. is this planned to be added eventually as well?

[xiaoxiangmoe]

@barbieri Should we move .ruby-version and Gemfile to ios directory？

[barbieri]

while one could move, it's usually better hosted in the parent so everything that may use ruby in the repo uses the same base (not sure if there are any... but still)