improve data on author_handle.json files

Updated URLs, Email addresses, GitHub handles,
Mastodon handles, and locations of various IOCCC winning authors.

author/Dave_Decot.json

@@ -4,10 +4,10 @@
     "author_handle" : "Dave_Decot",
     "full_name" : "Dave Decot",
     "sort_word" : "decot",
-    "location_code" : null,
-    "location_name" : null,
+    "location_code" : "US",
+    "location_name" : "United States of America",
     "email" : null,
-    "url" : null,
+    "url" : "https://www.linkedin.com/in/dave-decot-a8715a45/",
     "alt_url" : null,
     "deprecated_twitter_handle" : null,
     "mastodon" : null,