Thank you for making this
Also, a11y support isn't just for "blind" or "disabled" users; it tends to make the page better for all users. This applies to everything really; for example while being able to tell coins apart by touch is critical for you, it's also pretty convenient for me at times, so this kind of coin design is better for everyone.
Yes! Although I'm not "officially" disabled, I'm "blind" to my screen when I'm driving (you'll be happy to know), I'm half-blind to a message that pops on my screen when I'm drying off from a shower (no glasses in the shower is my motto), I'm "mute" when surrounded by strangers on a train, my fingers can't operate a mouse or keyboard when I'm doing dishes, etc., etc.
We're ALL disabled, and our circumstances change over very-short to very-long term as well. Having things designed with flexible interface options was one of the original goals of the web. Some of us remember before CSS, the publisher was supposed to specify semantics, and the user was supposed to specify presentation. I don't think we should go to that extreme, but I'd like to see our browsers, tools, and frameworks designed to make multi-UI flexibility easier and more common.
One tool I'd suggest looking into when getting started is Accessibility Insights for Web. A team at Microsoft developed a free, OSS browser extension for automatically detecting most common accessibility issues on your site: https://accessibilityinsights.io/docs/web/overview
Disclaimer: I do work at Microsoft, but my only affiliation with Accessibility Insights is as a happy customer :)
I immediately thought: how come none of the other browser vendors have something like this after all of this time?
Google develops Lighthouse, which, although an extension, I believe includes some a11y checks: https://developers.google.com/web/tools/lighthouse/
Similarly, Mozilla also promoted Webhint: https://webhint.io/ (which is cross-browser)
I'd also recommend Khan Academy's tota11y, which just works as a bookmarklet: https://khan.github.io/tota11y/