Edits will now use a different HTML -> markdown converter than what is
used to generate the body. This allows the plaintext body to have a
plain shortcode for custom emojis, while still having the raw data for
edits.
Additionally, for sent events, the raw input is saved locally, which
allows preserving commands and other such things. A future extension
may store the raw input in a custom field in the Matrix event to allow
lossless edits of messages sent from other clients.
