Recommend --data-binary flag when testing submit rules from curl

Change-Id: I446750051f9f8be7fdd8ef7a93307303c6746a2d
(cherry picked from commit b42e303d387287d3de4ca867cde745003af4357a)
diff --git a/Documentation/rest-api-changes.txt b/Documentation/rest-api-changes.txt
index 49ebb49..98dd21c 100644
--- a/Documentation/rest-api-changes.txt
+++ b/Documentation/rest-api-changes.txt
@@ -2574,6 +2574,17 @@
   ]
 ----
 
+When testing with the `curl` command line client the
+`--data-binary @rules.pl` flag should be used to ensure
+all LFs are included in the Prolog code:
+
+----
+  curl -X POST \
+    -H 'Content-Type: text/plain; charset=UTF-8' \
+    --data-binary @rules.pl \
+    http://.../test.submit_rule
+----
+
 [[list-drafts]]
 === List Drafts
 --