[docs] New quickstart page

[cartermp]

So, this is, uhh, a big change. I chatted with @austinlparker who wrote this article first, and he said we should rewrite it. So that's what this is!

Background: there's an effort in docs to standardize on how we do "get started" across the languages. In broad strokes:

• Get autoinstrumentation/instrumentation libs (whatever is best for the language) wired up to an HTTP server using the console exporter
• Augment that with a smidge of manual instrumentation
• Show how to spin up a local collector and send data to it
• Link to the other articles that go into more detail about automatic instrumentation/libraries, manual instrumentation, and exporting data

The otel-go getting started page is next up in this set of changes.

The approach I took here is sort of verbose - adding to the same bit of code a few times and showing the full sample in each relevant section. I think there's a benefit to that, in that at any given stage you have a fully working sample you can copy-paste into a file and run. But it does make the doc and changes larger. I am happy to consider alternatives.

@chalin, @svrnm, @austinlparker, @avillela -- would be good to get your eyes here as well. I validated that this works with no broken links in a local build of the website with these changes.

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• :white_check_mark: login: cartermp / name: Phillip Carter (78abaf7986781c262ec3dee7130ba117eb49cb0d, a9c40c2f80d110493650c521a4e55f398cf09558, fb1f28bc3dde358f0cbdb3062765df06f867d70d, c6d0693f6787f7661be25e54690b30675ad527a2, 554fceb6db35b8a97613df0ec9b24a86fe229485, 15f7c3d14652004701abf1681ec729929ec7af86)
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[avillela]

Added a couple of comments just to help clarify the narrative a bit more. Coming from the viewpoint of OTel noob who is desperately searching for a step-by-step example.

I did try out all 3 scenarios myself. Pretty solid overall!

[cartermp]

@hickeyma Yep! Will be addressing this soon. Still recovering from jetlag 🙂

[austinlparker]

Hey folks! Added a couple of little nitpicky comments, but I also ran through this whole thing stem to stern and it works on my machine ™️. Could we get this merged in so it can be brought into the page?

[MadVikingGod]

Sorry that this has fallen through the cracks. If I get time at the end of the day I will try and merge the last touches and just open an issue to resolve anything outstanding.