Add kaovilai maintainer details

[kaovilai]

Thank you for contributing to Velero!

Please add a summary of your change

Add @kaovilai maintainer details
Fix website maintainer thumbnails stretching (preview)

Does your change fix a particular issue?

Fixes #8328

Please indicate you've done the following:

• Accepted the DCO. Commits without the DCO will delay acceptance.
• Created a changelog file (make new-changelog) or comment /kind changelog-not-required on this PR.
• Updated the corresponding documentation in site/content/docs/main.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.96%. Comparing base (d0cffa3) to head (4071435).
Report is 6 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #8377   +/-   ##
=======================================
  Coverage   58.96%   58.96%           
=======================================
  Files         367      367           
  Lines       38895    38895           
=======================================
  Hits        22933    22933           
  Misses      14500    14500           
  Partials     1462     1462           

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