How can I use id and schema page of a yaml file in the devicetree bindings document?

[Chan Kim]

Hello all
In the file Documentation/devicetree/bindings/arm/primecell.yaml, I see in
the beginning,

# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/arm/primecell.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: ARM Primecell Peripherals

following the link in the id and schema just leads me to
https://www.devicetree.org/schema/# and it says 
"These are not the schemas you are looking for."

How can I open the links and use them?
Thanks a lot!
Regards,

Chan Kim