add mrsekut as a contributor for doc

[allcontributors[bot]]

Adds @mrsekut as a contributor for doc.

This was requested by keonik in this comment

[skip ci]

[github-actions[bot]]

:tada: This PR is included in version 1.7.0-alpha.1 :tada:

The release is available on:

• npm package (@alpha dist-tag)
• GitHub release

Your semantic-release bot :package::rocket:

[github-actions[bot]]

:tada: This PR is included in version 1.9.0-alpha.1 :tada:

The release is available on:

• npm package (@alpha dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: