[Docs] ArrayRemove: a note about non-primitive values

[louisameline]

Something which is pretty obvious for someone a little experience, but still might be worth a note in the docs:

state.array = [{ a: 1, b: 1 }]
dispatch('module/patch', { array: arrayRemove({ a: 1, b: 1 })})

Will remove the object at Firestore, but not locally, hence creating a sync issue.
This is how to do it:

state.array = [{ a: 1, b: 1 }]
dispatch('module/patch', { array: arrayRemove(state.array[0]) })

Same goes for arrayUnion, it is up to the user to check if the array doesn't already contain the value before triggering the action:

state.array = [.......]
const el = state.array.find(v => (v.a === 1 && v.b === 1)) || { a: 1, b: 1 }
dispatch('module/patch', { array: arrayRemove(el) })