Add page for JS benchmarks

[martinkuba]

The Javascript SDK now has microbenchmark tests that are automatically run on every push to main. The results are currently published at https://open-telemetry.github.io/opentelemetry-js/benchmarks/.

This PR adds a page here with the same results. This is similar to what has already been done for the Collector load tests.
https://opentelemetry.io/docs/collector/benchmarks/

[cartersocha]

@chalin could you take a look at the errors please?

[cartermp]

In this case you can look at the logs to see what failed, an npm run fix should take care of it.

[martinkuba]

@cartermp It looks like the spelling is failing on words that are part of the JS code. Is there a way to bypass that?

[cartermp]

Hrm. That should have fixed the spelling thing. Ugh, sorry.

In the yaml metadata at the top of the file, you can add:

cSpell:ignore: rrggbbaa Elems

[svrnm]

lgtm, only a minor change request.

Since this is the second benchmark page we should consider moving the CSS to a central place for that (maybe that also works for the JS piece?), not necessarily a part of this PR, but let's have a follow up issue