req: Easier setup and configuration for notification sender plugin

[colebow]

When trying to configure the Notification Sender, it's very unclear what the UI is asking for. The "Trigger Name" field is seemingly asking for a cron parameter, but is very particular about what it'll accept, with no documentation for how exactly it should be formatted. This is in contradiction to the plugin documentation saying no trigger arguments are required. The documentation also discusses needing webhook URLs, but the Explorer UI window seems to suggest wanting an API endpoint, which are also different from each other.