Doc: make explicit that remoteNameStyle is for non-Gerrit repos

The documentation already specify non-Gerrit examples of use
of remoteNameStyle; however, it does not say that if the remote
repository is backed by Gerrit, the *ONLY* supported option is
"slashes", otherwise the consequences could be catastrophic.

Two Gerrit servers (e.g. primary and replica) need to have
full alignment of repository names, as they are also referenced
in the inherited ACLs. Having a repository name mapping, may
disrupt the ACLs evaluation and make the remote Gerrit replica
unusable.

Bug: Issue 15318
Change-Id: I4d9447a4d0366a98037470c0cceda36f7a1b8a25
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index d606b7b..9fbede3 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -434,7 +434,8 @@
 remote.NAME.remoteNameStyle
 :	Provides possibilities to influence the name of the target
 	repository, e.g. by replacing slashes in the `${name}`
-	placeholder.
+	placeholder, when the target remote repository is not served
+	by Gerrit.
 
 	Github and Gitorious do not permit slashes "/" in repository
 	names and will change them to dashes "-" at repository creation