Update tutorials of both "Building a custom collector" and "Building a Trace Receiver"

[brightzheng100]

Re issue: #3488

This PR has two tutorials / files updated.

In "Building a custom collector":

1. Added the folder structure to help readers understand where the files should be properly located.
2. Added the further readings as the additional resources.

In "Building a Trace Receiver":

1. Streamlined & simplified the development process;
2. Applied the Go module / workspaces practices with a better folder structure;
3. Fixed many broken links due to a missing v in the path. For example: /blob/v{{% param collectorVersion %}}/pdata/;
4. Fixed other minor wording issues / typos.

[svrnm]

Hey @brightzheng100, thanks for taking the effort to improve those 2 documents, that's highly appreciated. I will try to provide you with a feedback soon.

@open-telemetry/collector-approvers please take a look as well!

[svrnm]

Overall it looks good to me. Please add telemetrygen to the cSpell:ignore list in line 5

@open-telemetry/collector-approvers PTAL!

[cartermp]

@open-telemetry/collector-approvers please take a look!

[svrnm]

I recently tried out the tracer receiver tutorial by using the updates from this PR and it worked just fine 👍

[jpkrohling]

Looks sane, but I didn't try this. Given that @svrnm did, I'm approving this, although I'd love to see the couple of changes I suggested.

[jpkrohling]

Should this URL be parameterized as well?

[brightzheng100]

That's a good idea but this URL might be stable enough to last for a while I believe.

[svrnm]

can this conversation be resolved?

[svrnm]

@brightzheng100 can you fix the merge conflicts?

[brightzheng100]

There are quite a lot of changes after my PR as it's been a while.

But I've tried to merge and test so you may have a final review and let me know if further changes are needed.

[cartermp]

@brightzheng100 I think if you run npm run fix it should clear up the rest. The content looks great to me, though. When those issues get fixed I'll merge it.

[brightzheng100]

Done!

I was seeing exceptions when running npm run fix, as attached below, so I stepped back by using only npm run fix:format and npm run serve to verify the contents before submitting.

But actually if I were to look into those exceptions, I should know how to fix those issues one by one based on the exception messages.

Not sure whether this is the right way like what I did (by looking into the exceptions) for contributors to review before git commit and git push, or there are some bugs in lint-md.

...
[10:52:14] Starting 'lint-md'...
/Users/brightzheng/workspaces/OSS/OpenTelemetry/opentelemetry.io-mine/content/en/docs/collector/custom-collector.md:162: MD040/fenced-code-language Fenced code blocks should have a language specified [Context: "```"]
/Users/brightzheng/workspaces/OSS/OpenTelemetry/opentelemetry.io-mine/content/en/docs/collector/building/receiver.md:201: MD034/no-bare-urls Bare URL used [Context: "https://github.com/rquedas/ote..."]
/Users/brightzheng/workspaces/OSS/OpenTelemetry/opentelemetry.io-mine/content/en/docs/collector/building/receiver.md:60: MD040/fenced-code-language Fenced code blocks should have a language specified [Context: "```"]
/Users/brightzheng/workspaces/OSS/OpenTelemetry/opentelemetry.io-mine/content/en/docs/collector/building/receiver.md:1121: MD040/fenced-code-language Fenced code blocks should have a language specified [Context: "```"]
[10:52:16] 'lint-md' errored after 1.83 s
[10:52:16] Error: Processed 364 files, 2 had issues.
    at Transform.<anonymous> (/Users/brightzheng/workspaces/OSS/OpenTelemetry/opentelemetry.io-mine/gulp-src/lint-md.js:152:15)
    at Transform.emit (node:events:526:35)
    at Transform.emit (node:domain:551:15)
    at endReadableNT (/Users/brightzheng/workspaces/OSS/OpenTelemetry/opentelemetry.io-mine/node_modules/through2/node_modules/readable-stream/lib/_stream_readable.js:1003:12)
    at process.processTicksAndRejections (node:internal/process/task_queues:82:21)

[cartermp]

Huh, interesting. Maybe it's a bug in the linting tool we use.