It'd help to include a copy of the license, rather than a link to some other website.
Legally, it is a bit of an issue as the linked license could technically change.
Technically, it prevents github from recognizing CC-BY-4.0 as the repository license.
> licensed under CC BY 4.0
> All of this is a starting point for a broader set of open source Mainboard documentation to enable creation of fully compatible third-party Mainboards in the future.
I don't see any full electronic schematics/BoM in the repo; they don't tell you how to replicate or modify the electronics, just how to fit the form factor.