config: Add unknown Action/SystemAction

Author: Drakulix

config/src/shortcuts/action.rs

@@ -130,6 +130,9 @@ pub enum Action {
 
     /// Change focus to the given workspace ID
     Workspace(u8),
+
+    #[serde(untagged, skip_serializing)]
+    Unknown,
 }
 
 /// Common system operations which may be controlled by system commands
@@ -179,6 +182,9 @@ pub enum System {
     WindowSwitcherPrevious,
     /// Opens the workspace overview
     WorkspaceOverview,
+
+    #[serde(untagged, skip_serializing)]
+    Unknown,
 }
 
 /// Defines the direction of an operation