Remove script for ReactiveHTML

[xavArtley]

from the doc:

Lifecycle callbacks
In addition to parameter callbacks there are a few reserved keys in the _scripts which are fired during rendering of the component:

'render': This callback is invoked during initial rendering of the component.

'after_layout': This callback is invoked after the component has been fully rendered and the layout is fully computed.

'remove' script should be exposed to delete eventListener recorded during previous steps