Enable Google Analytics 4 (GA4) for fluentbit.io and docs.fluentbit.io

[chalin]

This issue is for fluentbit.io. For why this is important & relevant, see:

• https://github.com/fluent/fluentd-website/issues/243

Tasks

• [x] Assess how best to update / add GA4 to main site fluentbit.io. Website info:
  • UA-181341719-2
  • Uses old analytics.js library, and hence cannot be linked to from GA4 ID
• [x] #25 - using CNCF GA4 site tag G-93T2VC0VBC
• [ ] docs.fluentbit.io - UA-181341719-3, which CNCF doesn't currently have access to. The docs are hosted by GitBook. The site tag needs to be changed to G-93T2VC0VBC. @edsiper and @erikbledsoe can either of you make this change?

/cc @caniszczyk @nate-double-u

[chalin]

/cc @toru-takahashi

[chalin]

Maybe this issue actually needs to be open over https://github.com/fluent/fluent-bit-website-hugo?

[toru-takahashi]

Fluent Bit is managed by @edsiper