Enable rsync for /feed

Debian patching in DX env requires the feed repo to be
synced between controllers. This commit enables that for us.

Test Plan:
Setup DX and run sw-patch commands to ensure that feed repo
is synced between controllers after every command

Story: 2009969
Task: 45866
Signed-off-by: Jessica Castelino <jessica.castelino@windriver.com>
Change-Id: Iac01d3f878eef33930d22a803a12d87b5ba0c79d

rsync-config/source-debian/rsyncd.conf

@@ -20,6 +20,12 @@ read only = yes
         uid = root
         read only = no
 
+[feed]
+        path = /var/www/pages/feed
+        comment = OSTree repo
+        uid = root
+        read only = no
+
 [repo]
         path = /var/www/pages/updates
         comment = Patching repo