[docs] Prepare docs

[colleenmcginnis]

Closes elastic/observability-docs#4057
Closes https://github.com/elastic/obs-docs-team/issues/239

Builds out minimal viable docs.

What's included

This includes the overall structure of the initial doc set. There is some missing information. I've left code comments with questions to be answered throughout the files.

Read more about what needs to be included in these docs in Elastic Distributions for OpenTelemetry (Mini docs style guide) (internal doc).

To do

• @colleenmcginnis convert back to AsciiDoc
• @colleenmcginnis add initial outline with questions for the dev team in code comments
• @colleenmcginnis continue clean up / aligning across languages
• @elastic/apm-agent-node-js review content that's already there, add content that's missing (especially where there are questions in code comments)
  • Feel free to either commit directly to this PR or add suggestions in PR comments — whichever works best for you!
• @colleenmcginnis clean up content
• 🆕 @colleenmcginnis convert to Markdown
• 🆕 @colleenmcginnis reorganize content as needed to be consumed on GitHub
• 🆕 @colleenmcginnis slight content reframing
• 🆕 @colleenmcginnis update product naming as needed
• @elastic/apm-agent-node-js final review, approve
• @colleenmcginnis request edit to blog (comment)
• @colleenmcginnis merge

[colleenmcginnis]

👋 @elastic/apm-agent-node-js can you please take an initial look here? I left many questions for you in code comments throughout the doc files. As you read through, if you have answers to questions, feel free to either commit directly to this PR or add suggestions in PR comments — whatever works best for you!

[trentm]

For better or worse, there is a link to the getting-started.mdx doc in the https://www.elastic.co/observability-labs/blog/elastic-opentelemetry-distribution-node-js blog post (see "Please try it out" in the bottom section) that will have to get updated when this is merged.

[colleenmcginnis]

I added this to the "To do" checklist above.

[colleenmcginnis]

Thanks for your patience here! I've updated the "To do" list above with some 🆕 items that reflect some recent changes to how we're approaching documenting Elastic Distributions for OpenTelemetry. This includes converting from AsciiDoc to Markdown. Users will be directed to this repo to read the docs on GitHub. We're not going to build and host these docs on elastic.co/guide right now.

[colleenmcginnis]

@trentm I left some questions for you below. I know you put a lot of thought into reviewing these changes to the docs already, so I didn't want to make too many more changes (besides translating to Markdown) without your input!

[trentm]

Sorry for the delay in responding, @colleenmcginnis.

[colleenmcginnis]

@trentm I split the naming changes into two commits: update naming (docs files) and update naming (non-docs files) so we can easily revert if you want to handle non-docs files separately.

[colleenmcginnis]

@trentm I don't have permission to merge in this repo. Feel free to merge when you're ready.