As a team member, I want to collaborate with multiple users on a proposal simultaneously so that we can work together efficiently and effectively.
Acceptance Criteria:
* Multiple users can access and edit the same proposal document simultaneously.
* Real-time updates are visible to all users.
* Changes made by each user are tracked and highlighted.
* Users can leave comments and suggestions on specific sections.
* The system maintains version control to track changes over time.
* Notifications are sent when significant changes are made to the proposal.
* Users can assign specific sections of the proposal to different team members.