feat: impl docs (#4)

The entire public api is covered with documentation in two languages - Russian and English.

the library now supports the latest three versions of python - 3.12, 3.13 and 3.14

minor design changes: now, when a Boolean flag is entered, its value is an empty string, not None.

tests have been adapted to the supported versions of python, readmi has been redesigned in two languages, German is no longer available.

src/argenta/router/command_handler/entity.py

@@ -1,3 +1,5 @@
+__all__ = ["CommandHandler", "CommandHandlers"]
+
 from collections.abc import Iterator
 from typing import Callable
 
@@ -30,9 +32,7 @@ class CommandHandlers:
         Private. The model that unites all CommandHandler of the routers
         :param command_handlers: list of CommandHandlers for register
         """
-        self.command_handlers: list[CommandHandler] = (
-            command_handlers if command_handlers else []
-        )
+        self.command_handlers: list[CommandHandler] = command_handlers if command_handlers else []
 
     def add_handler(self, command_handler: CommandHandler) -> None:
         """