Printing error caused by incorrectly named variable

[Steve-MP]

Printing of a render-rev-highlight component currently displays "undefined" because the variable containing the HTML content is incorrectly named.

Line 356-358 of render-rev-highlight.js should be:

       ${this._highlight.contents
          .map(({ html: htmlContent }) => `<article>${htmlContent}</article>`)
          .join('')}

I don't have permission to fork or upload a branch or I would've submitted a pull request.