Add Jinhong Kim as maintainer for Longhorn

[innobead]

Checklist for maintainer updates

• You've provided a link to documentation where the project has approved the maintainer changes.
• The maintainer(s) also created or updated their LFX Individual Dashboard profile.
• You've sent an email with the list of email address(es) to cncf-maintainer-changes@cncf.io for invitations to Service Desk and mailing lists. You can just mark this complete if you are only removing people.
• Optional: You've also sent a PR with affiliation updates to cncf/gitdm.

Maintainer Change Details

• Project: Longhorn
• New Maintainer: Jinhong Kim
• Email: jinhong.kim0@navercorp.com
• GitHub Username: @hookak
• Company: NAVER

[netlify]

✅ Deploy Preview for cncf-license-exceptions canceled.

Name	Link
🔨 Latest commit	02d5bbb
🔍 Latest deploy log	https://app.netlify.com/projects/cncf-license-exceptions/deploys/6a56d272effb930008631621

[riaankleinhans]

https://github.com/longhorn/longhorn/blob/master/MAINTAINERS