Multiple assignees update (#125)

* Documentation edits made through Mintlify web editor

* Documentation edits made through Mintlify web editor

---------

Co-authored-by: mintlify[bot] <109931778+mintlify[bot]@users.noreply.github.com>

assignment.mdx

@@ -19,3 +19,7 @@ We recommend turning sticky assignment off if your team has a shared support rot
 If you have sticky assignment on but are going on holiday you can turn on Away Mode in the top left menu within Plain. This will unassign you from any threads that come back to Todo.
 
 If you are interested in building fully automated bots using Plain, you can also programmatically assign threads to machine users as a starting point. If this sounds like an interesting use-case to you, please reach out to us via [email protected].
+
+**Multiple Assignees**
+
+You can add multiple assignees (lead and co-assignees) to threads. Having the ability to add multiple assignees improves your ability to collaborate internally on customer requests, and speeds up your team's response times.