fix the missing notes about telegram.ext.JobQueue

[beiluonever]

if not use pip install python-telegram-bot[job-queue] to install PTB, will get AttributeError: 'NoneType' object has no attribute 'get_jobs_by_name' error in this example.

Checklist for PRs

• Added .. versionadded:: version, .. versionchanged:: version or .. deprecated:: version to the docstrings for user facing changes (for methods/class descriptions, arguments and attributes)
• Created new or adapted existing unit tests
• Documented code changes according to the CSI standard
• Added myself alphabetically to AUTHORS.rst (optional)
• Added new classes & modules to the docs and all suitable __all__ s

If the PR contains API changes (otherwise, you can delete this passage)

• New classes:

  • Added self._id_attrs and corresponding documentation
  • __init__ accepts api_kwargs as kw-only

• Added new shortcuts:

  • In Chat & User for all methods that accept chat/user_id
  • In Message for all methods that accept chat_id and message_id
  • For new Message shortcuts: Added quote argument if methods accepts reply_to_message_id
  • In CallbackQuery for all methods that accept either chat_id and message_id or inline_message_id

• If relevant:

  • Added new constants at telegram.constants and shortcuts to them as class variables
  • Link new and existing constants in docstrings instead of hard coded number and strings
  • Add new message types to Message.effective_attachment
  • Added new handlers for new update types
    • Add the handlers to the warning loop in the ConversationHandler
  • Added new filters for new message (sub)types
  • Added or updated documentation for the changed class(es) and/or method(s)
  • Added the new method(s) to _extbot.py
  • Added or updated bot_methods.rst
  • Updated the Bot API version number in all places: README.rst and README_RAW.rst (including the badge), as well as telegram.constants.BOT_API_VERSION_INFO
  • Added logic for arbitrary callback data in tg.ext.Bot for new methods that either accept a reply_markup in some form or have a return type that is/contains telegram.Message

[Bibo-Joshi]

Hi, thanks for finding this mistake in out docs! Let's align the change with the other examples :)

[beiluonever]

Hi, thanks for finding this mistake in out docs! Let's align the change with the other examples :)

already applied suggestions, thanks .

[Bibo-Joshi]

Many thanks again :)