Escape curly braces in 2.11 release notes

Otherwise the line may not be rendered at all.

Change-Id: I8cb68ccfd5a80a552794628d4fb6114c5154af86
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
diff --git a/ReleaseNotes/ReleaseNotes-2.11.txt b/ReleaseNotes/ReleaseNotes-2.11.txt
index 3bc6c96..90519dc 100644
--- a/ReleaseNotes/ReleaseNotes-2.11.txt
+++ b/ReleaseNotes/ReleaseNotes-2.11.txt
@@ -486,7 +486,7 @@
 * Plugins can provide project-aware top menu extensions
 +
 Plugins can provide sub-menu items within the 'Projects' context. The
-'${projectName}' placeholder is replaced by the project name.
+'$\{projectName\}' placeholder is replaced by the project name.
 
 * Auto register static/init.js as JavaScript plugin.
 +