This is something everyone should read: Inclusive Design Principles.
It’s a set of design principles for the web and software. The principles are simple, well worded, and ensure that websites and software work for everyone, including folks with disabilities. This also makes for websites and software that work better for everyone, even folks without constraints.
The inclusive design principles were written by the Paciello Group, and if you want to read further, they’ve written some blog posts that go into more detail:
I’m putting a Dear Software Makers tag on this because this is something that everyone should read. Just sayin’.