Add page for other languages

[svrnm]

Addresses #1807

Preview:

• https://deploy-preview-2062--opentelemetry.netlify.app/docs/instrumentation/other/
• Registry examples: Perl, Julia

copying your comments from there @chalin:

For unofficial implementations that are sufficiently well developed, we could grant them their own page.

This sounds like a potential step 2, but we need to see if those sufficiently well developed projects move to become an "official" implementation eventually.

For all others, I'd mention them on the Instrumentation page.

Putting it there prominently enough without taking space for other important concerns was not possible, so I created a standalone page

We can always start by listing all of the unofficial implementations on the Instrumentation page and then promote them progressively to their own language-landing page.

I thought about having them in the registry first. This is already a place where we list inofficial things.

We might need some (at least minimal) guidelines for deciding which languages get promoted.
The GC might need to be involved? WDYT @austinlparker?

I solved that by pointing out that there are already 3 issues for languages that want to have a SIG and saying that if you have interest, please raise another one.

[cartermp]

Will approve as-is!

[cartermp]

Suggested change

	title: OpenTelemetry for haskell
	title: opentelemetry-haskell

to match the project name