Guides and Resources - acquia/reservoir GitHub Wiki
Official documentation
Release blog post
Guides
JSON API
Drupal module documentation https://www.drupal.org/docs/8/modules/json-api/json-api
Video series on JSON API https://www.youtube.com/playlist?list=PLZOQ_ZMpYrZsyO-3IstImK1okrpfAjuMZ