End User guide, in section 3.2.1. What is a devfile says:

The devfile can be saved in the root folder of a Git repository, a feature branch of a Git repository, a publicly accessible destination, or as a separate, locally stored artifact.

it would be nice to point specific devfile:

The devfile.yaml can be saved in the root folder of a Git repository, a feature branch of a Git repository, a publicly accessible destination, or as a separate, locally stored artifact.