DuckDuckGo support

[TheDeviantCrafter]

Describe the problem you're trying to solve

Shortcuts are not supported on DuckDuckGo.com

Describe the solution you'd like

Add shortcuts to DuckDuckGo.com

Describe alternatives you've considered

DDG does have some shortcuts built in, but they're not nearly as powerful as Web Search Navigator.

Additional context

DDG is the default search engine on Firefox which makes this more compelling than most of the other Google search alternatives. This will be even more true if people switch from Chrome after Manifest V3 nerfs adblock extensions.