Rename Atlas to Relay Search on check.torproject.org

Rename Atlas to Relay Search on check.torproject.org.

at the bottom of the page it says "For more information about this exit relay, see: Atlas. " but "Atlas" should be renamed to "Relay Search"

!https://check.torproject.org/?lang=en_US

Trac:
Username: Dbryrtfbcbhgf