Document Notification banner requires Javascript

[kr8n3r]

For complete functionality, Notification banner requires Javascript. This requirement is not documented.

[vanitabarrett]

More info from @kr8n3r (from Slack) on what they were expecting to see:

that it requires js to be fully functional for most scenarious. that is not mentioned plus then you need to dig into code to find out what it's export name is. i think a line on js requirement and initialisation ( auto when importing all or specific for module only) should be there

[vanitabarrett]

This probably applies to more than just the notification banner.

[querkmachine]

This is also the case with the Error summary and Skiplink components.