[receiver/zipkin][exporter/zipkin] Add codeowners to zipkin components

[atoulme]

Component(s)

exporter/zipkin, receiver/zipkin

Describe the issue you're reporting

The zipkin components do not have explicit codeowners besides the approvers. It would be best to have several members of the community step up to become explicit codeowners of those components, as we distribute them with the core and contrib distributions.

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

[MovieStoreGuy]

I'm happy to be a code owner for this, but I would appreciate some extra hands on this.

[andrzej-stencel]

Incidentally, I've just dipped my toes in these two components, fixed some docs issues:

• [chore] [receiver/zipkin] fix configuration docs #22701
• [chore] [exporter/zipkin] fix configuration docs #22703

Given that there are currently no code owners at all, I'm willing to help @MovieStoreGuy with it

[crobert-1]

I can help out as well 👍

[MovieStoreGuy]

Let me raise a PR to include the three of us.