docs: Updated Fluent Bit docs to use official plugin + Sandbox

[Jayclifford345]

We now recommend using the official Fluent Bit plugin since the Fluent Bit community actively maintains it and is now more feature-rich than the community plugin. The update:

• Moved community plugin to its own page for users still using the community plugin
• Updated _index to give examples using the official fluent bit plugin
• Added interactive sandbox

Sandbox preview for testing: https://killercoda.com/grafana-dev-testing/course/loki/fluentbit-loki-tutorial

Note link to the sandbox will fail in docs will fail with a 404 since we have not pushed the sandbox to production

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• For Helm chart changes bump the Helm chart version in production/helm/loki/Chart.yaml and update production/helm/loki/CHANGELOG.md and production/helm/loki/README.md. Example PR
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[JStickler]

[docs team] I'm only partway through this review, but I'm already hopelessly confused as to which plugin we're recommending. The naming conventions don't seem to be consistent between the files. I'm unclear on the difference between "official" and "community" or where you obtain either plugin. And if we're recommending one plugin over the other, why are we documenting both?
If there is some reason to document both, then we should turn the `_index" page into a landing page that briefly explains the difference between the two, and have the two plugin pages and the tutorial as child pages.

[Jayclifford345]

Hi @JStickler, I think the PR is ready for another review. I added the index page we discussed in our meeting and did a bit of rewording around how we position each of the plugins. Let me know what you think!

[JStickler]

[docs team]

[Jayclifford345]

Aaah thanks for all the typo catches again @JStickler, classic me. Thats them all accepted and ready for your review.

[JStickler]

[docs team] LGTM

[JStickler]

[docs team] Thanks for that last little fix. LGTM.