Add non-specific locale links to Mozilla docs

[pdehaan]

It seems like the data types always return MDN links (yay!), but MDN is pretty awesome at inferring the user's locale and serving up the best solution automatically, so it'd be nice if we could drop the /en-US/ bit and let MDN handle it.

### getTelemetryId

Returns **[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** the telemetry client ID

I tried searching the codebase, but couldn't find where/how we were generating those URLs.

---

$(npm bin)/documentation --version # 5.3.3
$(npm bin)/documentation build 'src/**' -f md --parse-extension=jsm -o docs/api.md

[tmcw]

Sure! The links to builtins are handled by the globals-docs module, and in the globals-docs.json file.

[pdehaan]

You've been served! documentationjs/globals-docs#4

[tmcw]

Included in 5.3.5!