[Feature Request] Custom script/notification hook

[coffeepenbit]

Describe the feature The feature would add another field in the section below that allows the user to point to a file/script that the Speedtest-Tracker would call.

Additional context This would allow for users to:

• Add their own (currently) unsupported method of being notified, e.g., Pushover
• Run a separate process that may not be considered a notification, e.g., have a smart switch reset a router whenever executed.

In general, it provides flexibility to the user without requiring the developers of this app to implement solutions for all permutations of notification services.