Use keyboard shortcuts for deleting and editing snippets in skim search

[Ninjani]

Skim v0.9.0 allows custom keybindings. Would be nice to use this in the-way search such that

• Shift-Left deletes a snippet (after asking for confirmation)
• Shift-Right edits a snippet
• Enter copies a snippet (as it is now)

This key logic needs to be added to the search function in the_way/search.rs

(Can't mess with defaults)