Misc changes

Fixing gnbsim reference
Adding sdcore logo image
separated configuration section

Change-Id: Ib6ec73d8528a3e197c0e19be6a3ee7c1942c6211
diff --git a/configuration/config_simapp.rst b/configuration/config_simapp.rst
new file mode 100644
index 0000000..28bef33
--- /dev/null
+++ b/configuration/config_simapp.rst
@@ -0,0 +1,67 @@
+Configuration using Simapp POD
+==============================
+
+Easiest way to configure SD-Core is to use simapp. Simapp is the POD which takes
+yaml configuration and configures the subscribers, device groups, network slices
+
+.. code-block::
+
+  config:
+    simapp:
+      cfgFiles:
+        simapp.yaml:
+          configuration:
+            provision-network-slice: true
+            sub-provision-endpt:
+              addr: config4g
+              port: 5000
+            subscribers:
+            - ueId-start: 208014567891201
+              ueId-end: 208014567891211
+              plmnId: 20801
+              opc: "d4416644f6154936193433dd20a0ace0"
+              op: ""
+              key: "465b5ce8b199b49faa5f0a2ee238a6bc"
+              sequenceNumber: 96
+            device-groups:
+            - name:  "4g-oaisim-user"
+              imsis:
+                - "208014567891201"
+                - "208014567891202"
+              ip-domain-name: "pool1"
+              ip-domain-expanded:
+                dnn: internet
+                dns-primary: "8.8.8.8"
+                mtu: 1460
+                ue-ip-pool: "172.250.0.0/16"
+                ue-dnn-qos:
+                  dnn-mbr-downlink: 20000000
+                  dnn-mbr-uplink: 4000000
+                  bitrate-unit: bps
+                  traffic-class:  #default bearer QCI/ARP
+                    name: "platinum"
+                    qci: 9
+                    arp: 1
+                    pdb: 300
+                    pelr: 6
+              site-info: "aiab"
+            network-slices:
+            - name: "default"
+              slice-id:
+                sd: "010203"
+                sst: 1
+              site-device-group:
+              - "4g-oaisim-user"
+              site-info:
+                gNodeBs:
+                - name: "aiab-gnb1"
+                  tac: 1
+                plmn:
+                  mcc: "208"
+                  mnc: "01"
+                site-name: "aiab"
+                upf:
+                  upf-name: "upf"
+                  upf-port: 8805
+
+