The homepage has this stated:

Accessibility out of the box

These standards were built with a priority on 508 compliance and ADA accessibility at every step of the design process. From colors to code, everything you need to meet high standards of accessibility are baked into these tools.

However, the accessibility work has nothing to do with Americans with Disabilities Act (ADA), just Section 508 of the Rehabilitation Act, so it should be removed.

Also a note from @rusty1992 stated: Should be Section 508 conformance not compliance. Agencies comply with the law when procuring products and services and industry and development conforms with the requirements.

One option:

These guidelines were built with a priority on accessibility in conformance with Section 508 Standards.

Another option:

These guidelines were built with a priority on accessibility at every step of the design process in conformance with Section 508 Standards.