Check-list for PRs

• Added .. versionadded:: NEXT.VERSION, .. versionchanged:: NEXT.VERSION, .. deprecated:: NEXT.VERSION or ``.. versionremoved:: NEXT.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 new classes & modules to the docs and all suitable __all__ s
• Checked the Stability Policy in case of deprecations or changes to documented behavior

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

• Checked the Bot API specific sections of the Stability Policy
• Created a PR to remove functionality deprecated in the previous Bot API release (see here)
• New Classes
  • Added self._id_attrs and corresponding documentation
  • __init__ accepts api_kwargs as keyword-only
• Added New Shortcuts
  • In telegram.Chat & telegram.User for all methods that accept chat/user_id
  • In telegram.Message for all methods that accept chat_id and message_id
  • For new telegram.Message shortcuts: Added quote argument if methods accept reply_to_message_id
  • In telegram.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
  • Linked new and existing constants in docstrings instead of hard-coded numbers and strings
  • Added new message types to telegram.Message.effective_attachment
  • 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

Polls

• Added the classes InputMediaSticker, InputMediaLocation, and InputMediaVenue.
• Added the class PollMedia, representing a media in a poll.
• Added the field media to the class Poll, allowing bots to see media in polls.
• Added the field explanation_media to the class Poll, allowing bots to see media in quiz explanations.
• Added the field media to the class PollOption, allowing bots to see media in poll options.
• Added the class InputPollMedia and the parameters media and explanation_media to the method sendPoll, allowing bots to add media to polls.
• Added the class InputPollOptionMedia and the field media to the class InputPollOption, allowing bots to add media to poll options.
• Added the field members_only to the class Poll.
• Added the parameter members_only to the method sendPoll.
• Added the field country_codes to the class Poll.
• Added the parameter country_codes to the method sendPoll.
• Decreased the minimum number of poll options from 2 to 1.