Ability to append/remove from default urlShorteners

[vincer]

You can only fully override urlShorteners currently so if you're just looking to add (or remove) one, you need to find the default list and copy/paste it into your config. This is both a bit onerous and additionally means that you won't get future updates to the default list.

My own example is that I want to add applications.zoom.us as an url shortener but not change the defaults.

Maybe urlShorteners can optionally take a method that has the defaults as an argument:

({defaultShorteners}) => defaultShorteners.concat(["applications.zoom.us"])

[johnste]

Released in 3.2.0