Sites that may have content authored from various individuals can be accommodated by using data files.
To attribute an author to a post or page that is different from the site author specified in _config.yml:
Step 1. Create _data/authors.yml and add authors using the following format. Anything variables found under author in _config.yml can be used (e.g. name, avatar, uri, social media profiles, etc.).
# /_data/authors.yml
Billy Rick:
name: "Billy Rick"
picture: "/images/bio-photo-2.jpg"
Cornelius Fiddlebone:
name: "Cornelius Fiddlebone"
picture: "/images/bio-photo.jpg"
Step 2. Assign one of the authors in authors.yml to a post or page you wish to override the site.author with.
Example: To assign Billy Rick as an author for a post the following YAML Front Matter would be applied:
author: Billy Rick