Add "For Researchers" landing page

[tkaragianes]

Summary

Add "For Researchers" landing page to support efforts to engage researcher contacts.

Implementation Notes

Static page implemented as in the "For Educators" page. One note, we don't currently have a contact form page, so the "Contact Us" link is a mailto: link to our [email protected] address.

Testing

Tested visually on local dev environment, matches design.