- Update the skeleton structure to match the new template system.
- Add a --format flag to the `hugo new theme` command to control the
format of the site configuration and default archetype files.
- Remove theme.toml. This file's presence can be confusing for new
users, and the README in the themes repository already has an example.
- Remove the LICENSE and README files from the skeleton. These files
are not needed for a theme to work, and they can be added later by
the user if desired.
Closes #13489
Closes #13544