Add docs for systems

sea_transport/system/auth_system.h

@@ -6,19 +6,66 @@
 #include "../entities/user_entity.h"
 
 
+/**
+ * @brief User's manipulation subsystem
+ * 
+ */
 class auth_system {
 private:
+    //! Subsystem's users collection
     QVector<user_entity> _users;
 public:
+    /**
+     * @brief Construct a new auth system object
+     * 
+     */
     auth_system() = default;
 
+    /**
+     * @brief Get user
+     * 
+     * @param login user's login
+     * @param success operation success reference
+     * @return user_entity* 
+     */
     user_entity* get_user(const QString &login, bool &success);
+    /**
+     * @brief Remove user from subsystem
+     * 
+     * @param login user's login
+     * @return true 
+     * @return false 
+     */
     bool remove_user(const QString &login);
+    /**
+     * @brief Registeer new user in system
+     * 
+     * @param login new user's login
+     * @param password new usere's password
+     * @param role new user's role
+     * @return true 
+     * @return false 
+     */
     bool register_user(const QString &login, const QString &password, UserRole role);
 
+    /**
+     * @brief Get subsystem immutable users collection
+     * 
+     * @return const QVector<user_entity>& 
+     */
     const QVector<user_entity>& users() const;
 
+    /**
+     * @brief Reads subsytem's data from disk
+     * 
+     * @param stream read stream
+     */
     void deserialize_data(QDataStream *stream);
+    /**
+     * @brief Writes subsytem's data to disk
+     * 
+     * @param stream write stream
+     */
     void serialize_data(QDataStream *stream);
 };