What kind of feature are you missing? Where do you notice a shortcoming of PTB?

API 10.0

Describe the solution you'd like

Guest Mode (@Poolitzer)

• Introduced support for guest mode, allowing bots to receive certain messages and issue replies within chats they are not a member of.
• Added the field supports_guest_queries to the class User.
• Added the fields guest_bot_caller_user and guest_bot_caller_chat to the class Message.
• Added the field guest_query_id to the class Message.
• Added the field guest_message to the class Update.
• Added the class SentGuestMessage and the method answerGuestQuery.

Chat Management (@harshil21)

• Added the field can_react_to_messages to the classes ChatMemberRestricted and ChatPermissions.
• Added the parameter return_bots to the method getChatAdministrators.
• Added the method deleteAllMessageReactions.
• Added the method deleteMessageReaction.
• Added the ability to see certain messages sent by other bots in groups.

Polls (@aelkheir)

• 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.

Live photos (@harshil21)

• Added the class LivePhoto, which represents a photo with a short video.
• Added the class InputMediaLivePhoto.
• Added the field live_photo to the classes Message and ExternalReplyInfo.
• Added the method sendLivePhoto, allowing bots to send live photos.
• Added the class PaidMediaLivePhoto, which describes a paid media with a live photo.
• Added the class InputPaidMediaLivePhoto, allowing bots to send live photos as paid media.
• Allowed to use live photos in sendMediaGroup and editMessageMedia,

General

• Allowed Business Bots to manage user accounts without a Telegram Premium subscription.
• Added the ability to send messages to other bots via username if both bots enabled bot-to-bot communication.
• Added the ability to reply to other bots from a business bot if the business bot enabled bot-to-bot communication.
• Allowed bots to pass an empty text in the method sendMessageDraft.
• Added the class BotAccessSettings and the method getManagedBotAccessSettings.
• Added the method setManagedBotAccessSettings.
• Added the method getUserPersonalChatMessages.

Describe alternatives you've considered

If you want to contribute, you can start from the Contribution Guide.

Additional context

Please comment below before start working on any part of the update so as to keep things in track and avoid double work.