Open items for completion

- [x] Readme and Usage guidlines
- [x] Port mapping testing
- [x] Unit Test cases
- [ ] Supporting specific network attachments
- [x] More hooks and extensions
- [ ] Evaluate use cases like these:
https://github.com/clearcontainers/runtime/blob/master/docs/architecture/architecture.md#cni . If we can make it easier for them to use cni through our library.
- [ ] Makefile,formats etc

Start by reviewing the unchecked items in this issue and the linked CNI architecture document. Clarify the scope of supporting specific network attachments, improving CNI use through the library, and adding Makefile or format support with the maintainers. Done means the agreed checklist items are implemented and verified.

Written by the indexing model from the issue text.