This commit extends the script used to generate thread
screenshots to be able to create invite_only streams,
add starred messages, create user groups, add edited
notice to messages, and send messages from notification
bots.
The window width is updated, and background for the
screenshots is changed to white.
It is also updated so that user-avatars mapping
occurs within the script itself.
This is a prep commit to #30128
Previously, we manually generated screenshots on /for/research
and other landing pages, which makes them difficult to maintain.
This PR adds a script - generate-user-messages-screenshot, which
expects the path of the filename containing the thread conversation
and path where screenshot needs to be generated, and generates
screenshot at the mentioned location.
Fixes#30016
Anders Kaseorg
roanster007
Alex Vandiver