Document how to send spoilers and custom emoji

readthedocs/examples/working-with-messages.rst

@@ -86,5 +86,40 @@ if you need a more in-depth explanation on how they work. Telethon only needs
 you to provide the emoji in some form. Some packages or websites can make this
 easier.
 
+
+Sending spoilers (hidden text)
+==============================
+
+The current markdown and HTML parsers do not offer a way to send spoilers yet.
+You need to use :tl:`MessageEntitySpoiler` so that parts of the message text
+are shown under a spoiler.
+
+The simplest way to do this is to `modify the builtin parsers`_ to support
+sending these new message entities with the features they already provide.
+
+
+Sending custom emoji
+====================
+
+The current markdown and HTML parsers do not offer a way to send custom emoji
+yet. You need to use :tl:`MessageEntityCustomEmoji` so that parts of the
+message text with emoji are replaced with a custom one instead.
+
+The simplest way to do this is to `modify the builtin parsers`_ to support
+sending these new message entities with the features they already provide.
+
+:tl:`MessageEntityCustomEmoji` must wrap an emoji in order to work (you can't
+put it around arbitrary ``"text"``, it won't work), so be sure to keep this in
+mind when using it.
+
+To find the ``document_id`` for the custom emoji, the simplest way is to send
+a message with an official client containing the custom emoji you want, and
+then print the ``message.entities`` to find the ``document_id``.
+
+If you prefer, you can also use :tl:`GetFeaturedEmojiStickers` to find about
+the ``document_id`` of featured custom emoji.
+
+
 .. _unicode-table.com: https://unicode-table.com/en/emoji/
 .. _emoji: https://pypi.org/project/emoji/
+.. _modify the builtin parsers: https://github.com/LonamiWebs/Telethon/wiki/Sending-spoilers-and-custom-emoji