Add a Data map[string]any field to store arbitrary data for a command.

command.go

@@ -111,6 +111,11 @@ type Command struct {
 	// command does not define one.
 	Version string
 
+	// Data are key/value pairs of arbitrary types that can be used by applications or "plugin" libraries
+	// that wish to store and use data associated with a given command. This data will thus share the same
+	// lifetime as the command itself.
+	Data map[string]any
+
 	// The *Run functions are executed in the following order:
 	//   * PersistentPreRun()
 	//   * PreRun()