Specify in docs that robot comments are deprecated

Release-Notes: skip
Change-Id: I68d24b5c2399ae6a012dcd1c8d5f3418a7177d8c
diff --git a/Documentation/config-robot-comments.txt b/Documentation/config-robot-comments.txt
index 04309e5..ef99d80 100644
--- a/Documentation/config-robot-comments.txt
+++ b/Documentation/config-robot-comments.txt
@@ -1,5 +1,9 @@
 = Gerrit Code Review - Robot Comments
 
+[NOTE]
+Robot Comments are deprecated in favour of link:pg-plugin-checks-api.html[Checks API] and human
+comments.
+
 Gerrit has special support for inline comments that are generated by
 automated third-party systems, so called "robot comments". For example
 robot comments can be used to represent the results of code analyzers.