Add Kostas Christidis as Fabric Maintainer

Kostas has been a stalwart reviewer for a long time and has definitely
earned a spot as a Fabric Maintainer to help keep the ordering service
reviews current. His reviews are always thoughtful and his work top
quality. He is also frequently helping people on RocketChat and email.

Change-Id: I8a476859144c64ac8c4d5d027caedc7201af69ca
Signed-off-by: Christopher Ferris <chrisfer@us.ibm.com>

docs/source/MAINTAINERS.rst

@@ -2,7 +2,7 @@ Maintainers
 -----------
 
 +---------------------------+---------------------+------------------+----------------+--------------------------------+
-| Name                      | Gerrit              | GitHub           | Slack          | email                          |
+| Name                      | Gerrit              | GitHub           | RocketChat     | email                          |
 +===========================+=====================+==================+================+================================+
 | Binh Nguyen               | binhn               | binhn            | binhn          | binhn@us.ibm.com               |
 +---------------------------+---------------------+------------------+----------------+--------------------------------+
@@ -20,6 +20,8 @@ Maintainers
 +---------------------------+---------------------+------------------+----------------+--------------------------------+
 | Jonathan Levi             | JonathanLevi        | JonathanLevi     | JonathanLevi   | jonathan@hacera.com            |
 +---------------------------+---------------------+------------------+----------------+--------------------------------+
+| Kostas Christidis         | kchristidis         | kchristidis      | kostas         | kostas@gmail.com               |
++---------------------------+---------------------+------------------+----------------+--------------------------------+
 | Sheehan Anderson          | sheehan             | srderson         | sheehan        | sranderson@gmail.com           |
 +---------------------------+---------------------+------------------+----------------+--------------------------------+
 | Srinivasan Muralidharan   | muralisr            | muralisrini      | muralisr       | muralisr@us.ibm.com            |