“All Categories” Option?

I was hoping there would be an option to display an “All Categories” option, as there is a great opportunity for this plugin to replace the default calendar widget (which is limited and doesn’t allow pagination).

Due to need, I’ve modified the code myself to enable an “All Categories” selection in the dropdown. If possible, I’d love to contribute to a GitHub of this, otherwise I’d love to see this to become built in for a future update.