matterhorn:
  media_path: /path/to/dir

encoding:
  working_file_path: /path/to/dir

home_page:
  featured_collections: ['col1_id', 'col2_id']
  carousel_collections: ['col3_id', 'col4_id', 'col5_id']

Choose which collections to display in the featured and carousel portions of the new homepage. 

More information on customizing the UI