Review of the 8.x-2.x branch (commit 4f3a179):
- Your README.txt does not follow best practices (headings need to be uppercase). See https://www.drupal.org/node/2181737 .
- The INSTALLATION section is missing.
- The CONFIGURATION section is missing.
- No automated test cases were found, did you consider writing PHPUnit tests? This is not a requirement but encouraged for professional software development.