Add AUTHORS file.

AUTHORS

@@ -0,0 +1,19 @@
+# This is the list of Vello's significant contributors.
+#
+# This does not necessarily list everyone who has contributed code,
+# especially since many employees of one corporation may be contributing.
+# To see the full list of contributors, see the revision history in
+# source control.
+Google LLC
+Raph Levien
+Chad Brokaw
+Arman Uguray
+Elias Naur
+Daniel McNab
+Spencer C. Imbleau
+Bruce Mitchener
+Tatsuyuki Ishi
+Markus Siglreithmaier
+Rose Hudson
+Brian Merchant
+Matt Rice