Add Comparison with Vuex

[ai]

We need to compare Storeon to Vuex in the docs since most of the Vue.js users will want to know it.

I see:

1. The size
2. Performance (do we subscribe to changes of specific store’s keys?)

[ai]

We also need to clarify what is Storeon in your docs, so people will not need extra click.

At least that it is state manager.

[distolma]

Fixed with 688205d commit