Update the description at the head of `AUTHORS`; ref
MODIFY
AUTHORS
AUTHORS
-Original Authors "mruby developers" are:
- Yukihiro Matsumoto
+This is the (likely incomplete) list of of "mruby developers".
+If you submit a patch to mruby, please add your name to the end
+of this list.
+
+ Yukihiro Matsumoto (Matz)
SCSK KYUSHU CORPORATION
Kyushu Institute of Technology
Network Applied Communication Laboratory, Inc.

Update the description at the head of `AUTHORS`; ref #4324