Make 'double-click' behave the same as 'enter' by default

Close #3061

src/options.go

@@ -1851,6 +1851,11 @@ func postProcessOptions(opts *Options) {
 	}
 	opts.Keymap = keymap
 
+	// If 'double-click' is left unbound, bind it to the action bound to 'enter'
+	if _, prs := opts.Keymap[tui.DoubleClick.AsEvent()]; !prs {
+		opts.Keymap[tui.DoubleClick.AsEvent()] = opts.Keymap[tui.CtrlM.AsEvent()]
+	}
+
 	if opts.Height.auto {
 		for _, s := range []sizeSpec{opts.Margin[0], opts.Margin[2]} {
 			if s.percent {

src/terminal.go

@@ -426,7 +426,6 @@ func defaultKeymap() map[tui.Event][]*action {
 	add(tui.SDown, actPreviewDown)
 
 	add(tui.Mouse, actMouse)
-	add(tui.DoubleClick, actAccept)
 	add(tui.LeftClick, actIgnore)
 	add(tui.RightClick, actToggle)
 	return keymap