Improve readme file

[jesper-friis]

Most users of oteapi-services would like to run it with Docker Compose in production mode. Place that section on top of the readme.

A more logical structure of the readme would be:

• One-liner - "A RESTfull interface to OTEAPI" + illustrative figure
• Table of content
• About oteapi-services
• Using oteapi
  • Run oteapi-services
  • OTEAPI Plugin Repositories
• For developers
  • Run oteapi-services as developer
  • For plugin developers
• Acknowledgements
• License

[CasperWA]

          Ok. Then the corresponding documentation for oteapi services should be updated.

Originally posted by @jesper-friis in SINTEF/entities-service#9 (comment)