Create RS820+.yaml (#488)

Synology RS820+ device type definition

device-types/Synology/RS820+.yaml

@@ -0,0 +1,36 @@
+---
+manufacturer: Synology
+model: RS820+
+slug: synology-rs820-plus
+part_number: RS820+
+u_height: 1
+is_full_depth: true
+subdevice_role: parent
+comments: '[RS820 Series Datasheet](https://www.synology.com/en-us/products/RS820+#specs)'
+power-ports:
+  - name: PSU 1
+    type: iec-60320-c14
+interfaces:
+  - name: Ethernet 1
+    type: 1000base-t
+  - name: Ethernet 2
+    type: 1000base-t
+  - name: Ethernet 3
+    type: 1000base-t
+  - name: Ethernet 4
+    type: 1000base-t
+device-bays:
+  - name: Sled 1
+  - name: Sled 2
+  - name: Sled 3
+  - name: Sled 4
+console-server-ports:
+  - name: Rear USB1
+    type: usb-a
+  - name: Rear USB2
+    type: usb-a
+  - name: Console
+    type: de-9
+    mgmt_only: true
+  - name: eSATA
+    type: other