Update NEHRP 2020 information box

On the nehrp-2020.html page, there is a blue information box, the text in this box should be updated as follows:

This web service is still under development. More specifically:

• The current web service output for American Samoa will be updated to its final version.
• Output of vertical ground motions is still under development.

Accordingly, this web service is for review purposes only and is not intended for application in engineering >projects at this time.