Github usernames are allowed to contain `-`, but the autocompletion was not working correctly. We added `-` as an allowed character for markdown files. We are not aware of any completions for markdown files, so this should be fine to add. Before:  After:  Release Notes: - Fixed autocompletion for usernames with dash character in the chat message editor Co-authored-by: Remco Smits <62463826+RemcoSmitsDev@users.noreply.github.com>