Update documentation

Issue-ID: NONRTRIC-543
Signed-off-by: ychacon <yennifer.chacon@est.tech>
Change-Id: I5ccc11fd8dc54ba7d83f448c9dadfbfcc62a6098
diff --git a/docs/installation-guide.rst b/docs/installation-guide.rst
index 686dc57..8cd0161 100644
--- a/docs/installation-guide.rst
+++ b/docs/installation-guide.rst
@@ -12,7 +12,7 @@
 
 
 The Non-RT RIC Control Panel is a graphical user interface that enables the user to view and manage the A1 policies in
-the RAN and also view producers and jobs for the Enrichement Information coordinator service. 
+the RAN and also view producers and jobs for the Enrichement Information coordinator service.
 
 Preface
 -------
@@ -21,6 +21,10 @@
 must be installed to make it work. See `Non-RT RIC <https://docs.o-ran-sc.org/projects/o-ran-sc-nonrtric/en/latest/index.html>`__
 for how to install and set them up.
 
+This guide is to install both the NonRtRIC Control Panel and the NonRtRIC Service Gateway.
+
+The installation of the NonRtRIC Service Gateway is needed as it exposes A1 Policy Management Service and Enrichment Coordinator Service.
+
 Software Installation and Deployment
 ------------------------------------