code: func (e *Empire) Set(ctx context.Context, opts SetOpts) (*Config, error) {
  	if err := opts.Validate(e); err != nil {
  		return nil, err
  	}
  
  	tx := e.db.Begin()
  
  	c, err := e.configs.Set(ctx, tx, opts)
  	if err != nil {
  		tx.Rollback()
  		return c, err
  	}
  
  	if err := tx.Commit().Error; err != nil {
  		return c, err
  	}
  
  	return c, e.PublishEvent(opts.Event())
  }
docs: // Set applies the new config vars to the apps current Config, returning the new
  // Config. If the app has a running release, a new release will be created and
  // run.