feat(docs): update otelcol docs

[sed-i]

Issue

Otelcol docs are slightly outdated, compared to what we have in otelcol-k8s docs.

Solution

Sync docs so they're up to date.

Checklist

• I have added or updated relevant documentation.
• PR title makes an appropriate release note and follows conventional commits syntax.
• Merge target is the correct branch, and relevant tandem backport PRs opened.