adds docs directory with dev guide

Change-Id: I1f2652cc471f3fa39627a63f09fefdd0b9f5bb6b
Marconi Operations Document

Adding developer/operation documents including:
1. Glossary
2. Install and configure
3. Deploy Marconi in a minimal HA env
4. Access API with Marconi client

Co-Authored-By: Fei Long Wang <flwang@cn.ibm.com>

Implements: blueprint docs

Change-Id: I2549995fb0754c7f3c8ce718639e1299e2805795
Merge "Marconi Operations Document"