Documentation should give an example of using `mocha` property in `package.json`

Is your feature request related to a problem or a nice-to-have?? Please describe. The documentation mentions the ability to use a property in package.json instead of a separate mocha.opts file.

Describe the solution you’d like I can’t find an example of actually doing this anywhere.

Describe alternatives you’ve considered It’s pretty hard to search online for people talking about “the mocha property in package.json”, since “package.json” is probably the single most common string in any page about Node tooling.

Additional context I’m specifically interested in how to specify flags that can be repeated, e.g. --file.

[akopchinskiy]

Mocha’s documentation about configs really sucks

[postspectacular]

It would be great to extend these example configs and show how this setup can be used to specify additional options for Node itself. I’ve been trying to enable the --experimental-wasm-simd option via any of the described config methods, but with no avail. How can this be done?