🚀 Feature: Add example of usage in a CommonJS project with Chai 5.x (ESM-only)

[JoshuaKGoldberg]

Following #75 -> #76: Chai 5.x is ESM-only and folks are asking about it (mochajs/mocha#5073). We should add an example or two showing how to use Mocha in a CommonJS project with ESM dependencies such as Chai.

Edit: chaijs/chai#1575 has an example of it working, fyi.

[compwron]

I am interested in this :)

[JoshuaKGoldberg]

@compwron still interested?

I sent #106 -> #107 for native require(ESM) support, but I think folks stuck on older Node.js versions would still be benefitted by an example showing how to do it.