Add CommandManager::ShowWhichKey and include src in build

src/app/editor/system/command_manager.h

@@ -1,6 +1,7 @@
 #ifndef YAZE_APP_EDITOR_SYSTEM_COMMAND_MANAGER_H
 #define YAZE_APP_EDITOR_SYSTEM_COMMAND_MANAGER_H
 
+#include <stack>
 #include <string>
 #include <unordered_map>
 
@@ -16,6 +17,8 @@ class Command {
 
 class CommandManager {
  public:
+  void ShowWhichKey();
+
   void RegisterCommand(const std::string& shortcut, Command* command) {
     commands_[shortcut] = command;
   }
@@ -50,4 +53,6 @@ class CommandManager {
 
 }  // namespace editor
 }  // namespace app
-}  // namespace yaze
+}  // namespace yaze
+
+#endif  // YAZE_APP_EDITOR_SYSTEM_COMMAND_MANAGER_H