Some steps to get branch working with the config plugin

### Summary

Hey guys I just wanna leave this here because I struggled a lot and I hope it helps someone out. I think a few things need to be added to the config plugin directions. If you just add the config plug the universal links do not work. Placing the associated domains in the config plugin did not do it for me. But putting them in the associatedDomains inside the ios object worked. Also make sure to configure the scheme. The snippet bellow shows the set up needed to get things working.

``` java script
export default {
name: 'appName',
slug: 'appName',
...
scheme: 'appname', // <----- make sure you specify the scheme
...
ios: {
associatedDomains: [ // <----- make sure you specify the associated domains like so
'applinks:exampleapp.test-app.link',
'applinks:exampleapp-alternate.test-app.link',
],
...
},
plugins: [
[
'@config-plugins/react-native-branch', // <----- place config plug in here like so
{
apiKey: 'key_test_YourKeyAwjB9dasdceAsoKE5J5', // <----- place apiKey here
},
],
],
```
}

### Config Plugin

@config-plugins/react-native-branch

### What platform(s) does this occur on?

iOS

### SDK Version

45

### Reproducible demo

https://github.com/haibert/BranchIssue