Added Include folder

*facepalm*

include/cmd/args/arg_manager.hpp

@@ -30,11 +30,16 @@ namespace fsh {
             if (flags.find(id) != flags.end()) return Argument<T>::get(flags[id]);
             return std::make_optional<T>();
         }
+
         bool get(const std::string& id) { return flags.find(id) != flags.end(); }
 
         void push_arg(std::shared_ptr<_Argument> arg) { pos_argument.push_back(arg); }
         void push_flag(const std::string& id, std::shared_ptr<_Argument> arg = nullptr) { flags[id] = arg; }
 
+        unsigned int size() {
+            return pos_argument.size();
+        }
+
       private:
         PosArgs  pos_argument;
         FlagOpts flags;