docs(readme): clarify synapse availability

Signed-off-by: Lars Trieloff <lars@trieloff.net>

Add aria label for the start button

Don't login after registration

Add ability to export logs from the console

Elaborate on what the "disable_composer_until_operator_join" option does

ComposerViewModel may be undefined

Instructions for setting up your homeserver

Add title and screenshot

Signed-off-by: Will Hunt <will@half-shot.uk>

Show tile when user leaves rooms

Prevent users from redacting messages sent by the operator

Update default chatterbox link

Signed-off-by: Travis Ralston <travisr@element.io>

Add support for disabling the composer until operator joins 

Pre release maintenance