use MMKV instead of AsyncStorage

[ryskin]

I had a problem in my project with the limitation of AsyncStorage that led to crashes, also it was really slow, but when I moved to MMKV all become really quick and stable.

I used this library https://github.com/ammarahm-ed/react-native-mmkv-storage

[jamonholmgren]

While we don't use MMKV for Ignite by default (since Expo doesn't support it), we do have an Ignite Cookbook recipe for it. Check it out:

https://infinitered.github.io/ignite-cookbook/docs/MigratingToMMKV

[ryskin]

I see, it makes sense. Thanks