add couchdb 2.3.1 based on raspbian:buster (fixes #41)

[lillyxxx]

Overview

Initialed the Dockerfile to support CouchDB 2.3.1

GitHub issue number

41

Checklist

• [x] Code is written and works correctly;
• [x] Changes are covered by tests;
• [ ] Documentation reflects the changes;

[dogi]

@lillyxxx the README.md needs some update too ;) also great job