Keysave
This module overrides the default browser save behavior (Ctrl+S or Cmd+S) to submit Drupal forms, including entity and configuration forms. This allows for quicker form saving without needing to click the submit button.
When working in a configuration or entity form, overrides the browser's default behaviour for command-s or control-s key combinations, to submit the form instead. The Javascript triggers a click on the submit button, so any validation or submit handlers should function normally. The behaviour is specifically targeted towards entity forms, configuration forms, and a number of other forms in Drupal's admin UI.
Similar Modules
The Hotkeys for Save module achieves a similar end, but makes no effort to target entity or admin forms, instead attaching its library to every site page for users with the permission to use it.