The ThisIs… theme and some of the plugins are released under the GNU General Public License Version 3 or the earlier version GPLv2.
The theme and some plugins are the original work of Herb Miller, @bobbingwide aka @vsgloik.
They have copyright statements in the main source files. eg.
(C) Copyright Herb Miller, Bobbing Wide 2021 Copyright 2010-2021 Bobbing Wide ( email : email@example.com )
The website content is the original work of Herb Miller, derived from existing material developed for Gutenberg and/or published on wordpress.org by hundreds of contributors.
Some of the images, such as the bears, are Copyright Herb Miller.
The screenshots were all taken by Herb Miller.
Site logo and motto
The site logo was developed by Andrew Leonard. He used Baskerville Old face; it’s similar to Mrs Eames, which is used in the WordPress logo.
The new motto is a screenshot of Mrs Eames. The wording was chosen by one of the bears.
This website was developed as educational material. I can’t see any reason why it cannot be copied and cobbled into official documentation, were it to be considered suitable for that purpose.