message: Update README.md
  add docker start to readme
diff: @@ -18,6 +18,16 @@ Documentation
  * [Website and Documentation](https://xacc.readthedocs.io)
  * [API Documentation](https://ornl-qci.github.io/xacc-api-docs/)
  +Quick Start with Docker
  +-----------------------
  +We provide docker images with XACC built and installed. These images by default serve
  +an Eclipse Theia IDE on port 3000. To get started, run
  +```bash
  +$ docker run --security-opt seccomp=unconfined --init -it -p 3000:3000 xacc/xacc
  +```
  +Navigate to ``https://localhost:3000`` to open the IDE and get started with XACC.
  +
  +
  Build from Source
  -----------------
  Full installation details can be followed [here](https://xacc.readthedocs.io/en/latest/install.html).
  