Summary:
Based on the issue here https://github.com/facebook/flipper/issues/967, I'm adding the flipper diagram to a documentation.
It should help explain briefly how does all parts communicate together and visualise key terms.
## Changelog
- Add Flipper architecture diagram to documentation
Pull Request resolved: https://github.com/facebook/flipper/pull/1073
Reviewed By: jknoxville
Differential Revision: D21278322
Pulled By: passy
fbshipit-source-id: 3cd8c71b2595b86911f5c9061bc2e8119da1d315
4d13b7ca2a
