Document Workflow for Training Portal

I need a document flow functionality for our internal employee training portal. The system should manage the approval and version control of the following documents:

- Scope of Work (SoW)
- Business Requirements Document (BRD)
- Functional Requirements Document (FRD)

Requirements:
- Document approval workflow
- Simple version control (major versions only)
- User-friendly interface

Ideal Skills:
- Experience in developing document management systems
- Strong understanding of workflow automation
- Proficiency in version control mechanisms

Please provide examples of similar work done.