docs: add Kethers as a contributor for code

[allcontributors[bot]]

Adds @Kethers as a contributor for code.

This was requested by nfrechette in this comment

[skip ci]

[commit-lint[bot]]

Documentation

• update README.md [skip ci] (50be409)
• update .all-contributorsrc [skip ci] (057fa30)

Contributors

allcontributors[bot]

Commit-Lint commands

You can trigger Commit-Lint actions by commenting on this PR: - `@Commit-Lint merge patch` will merge dependabot PR on "patch" versions (X.X.Y - Y change) - `@Commit-Lint merge minor` will merge dependabot PR on "minor" versions (X.Y.Y - Y change) - `@Commit-Lint merge major` will merge dependabot PR on "major" versions (Y.Y.Y - Y change) - `@Commit-Lint merge disable` will desactivate merge dependabot PR - `@Commit-Lint review` will approve dependabot PR - `@Commit-Lint stop review` will stop approve dependabot PR

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}