Mark Ann Horton -> Mary Ann Horton

Mary Ann Horton (who gave us uuencode, contributed to BSD Unix amongst
other things) is transgender and she goes by the name Mary Ann so the
website should also say that (it had (Mark) in it which was her
birth name).

Fixed the URL as well as the old one is no longer valid.

1994/horton/README.md

@@ -1,11 +1,8 @@
 # Best Utility
 
-Mark Horton  
-AT&T Bell Labs  
-Rm 1H-117  
-6200 E Broad St.  
-Columbus OH 43213  
-US  
+Mary Ann Horton  
+US 
+<https://maryannhorton.com>
 
 ## To build: