rtdb/lists.md#api-summary missing description

[4skinSkywalker]

Hi guys,

I'm reading the documentation at https://github.com/angular/angularfire2/blob/master/docs/rtdb/lists.md#api-summary

The description for the update method is missing (as it just says "Firebase").

[jamesdaniels]

@jhuleatt think you could address?

[jamesdaniels]

Dunno if we fixed but closing as outdated since we're revamping the docs for the new version.