Fix typo in EuiBasicTable documentation

[justinkambic]

Summary

Found a small typo in the props documentation for EuiBasicTable. This patch is intended to fix it.

Checklist

• This was checked in mobile
• This was checked in IE11
• This was checked in dark mode
• Any props added have proper autodocs
• Documentation examples were added
• A changelog entry exists and is marked appropriately
• This was checked for breaking changes and labeled appropriately
• Jest tests were updated or added to match the most common scenarios
• This was checked against keyboard-only and screenreader scenarios
• This required updates to Framer X components

[ryankeairns]

@justinkambic Thanks for fixing this! Since this is a docs-only change, you don't need the CHANGELOG entry.

[cchaos]

Since this is just a Docs change, it doesn't need a changelog.

[justinkambic]

CHANGELOG entry removed in 81ff5da.

Will merge when green.