More class based handlers

docs/dispatcher/class_based_handlers/basics.md

@@ -7,11 +7,16 @@ There are some base class based handlers what you need to use in your own handle
 
 - [BaseHandler](#basehandler)
 - [MessageHandler](message.md)
-
+- [CallbackQueryHandler](callback_query.md)
+- [ChosenInlineResultHandler](chosen_inline_result.md)
+- [InlineQueryHandler](inline_query.md)
+- [PollHandler](poll.md)
+- [PreCheckoutQueryHandler](pre_checkout_query.md)
+- [ShippingQueryHandler](shipping_query.md)
 
 ## BaseHandler
 
-Base handler is abstract class and should be used in all other class-based handlers.
+Base handler is generic abstract class and should be used in all other class-based handlers.
 
 Import: `#!python3 from aiogram.hanler import BaseHandler`
 
@@ -21,3 +26,11 @@ This class is also have an default initializer and you don't need to change it.
 Initializer accepts current event and all contextual data and which can be accessed from the handler through attributes: `event: TelegramEvent` and `data: Dict[Any, str]`
 
 If instance of the bot is specified in context data or current context it can be accessed through `bot` class attribute.
+
+
+### For example:
+```python3
+class MyHandler(BaseHandler[Message]):
+    async def handle(self) -> Any:
+         await self.event.answer("Hello!")
+```