docs: modify readme service list

Signed-off-by: Valentin Kunz <valentin.kunz@b-ite.de>

Author: Valentin Kunz

README.md

@@ -56,7 +56,6 @@ Included service implementations
     - Scoop.it!
     - Tumblr
     - Twitter
-    - Xing
     - Yahoo
 - OAuth2
     - Amazon
@@ -98,6 +97,7 @@ Included service implementations
     - Ustream
     - Vimeo
     - Vkontakte
+    - Xing
     - Yahoo
     - Yammer
 - more to come!