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.

docs/code_snippets/response/snippet3.py

@@ -0,0 +1,16 @@
+from argenta import Command, Response, Router
+
+router = Router(title="Get Data Example")
+
+
+@router.command(Command("info", description="Show all stored data"))
+def info_handler(response: Response):
+    # Get all data from global storage
+    all_data = response.get_data()
+
+    if all_data:
+        print("Stored data:")
+        for key, value in all_data.items():
+            print(f"  {key}: {value}")
+    else:
+        print("No data stored")