Validator Warnings

[emartinez-usgs]

Consider addressing W3C validator warnings generated by the current layout implementation.

• This document appears to be written in English. Consider adding lang="en" (or variant) to the html start tag
• The banner role is unnecessary for element header.
• The main role is unnecessary for element main.
• Section lacks heading. Consider using h2-h6 elements to add identifying headings to all sections.