Add configs for some banggood light switches:

- YK3_WIFI_SV2 (1 and 2 gang)
- YK3_WIFI_SV5 (3 gang)

fs/2gang.json

@@ -0,0 +1,8 @@
+{
+  "name": "2 Gang - YK3_WIFI_SV2",
+  "status_led": 0,
+  "channels": [
+    { "led": 16, "relay": 13, "button": 12 },
+    { "led": 2,  "relay": 15, "button": 5  }
+  ]
+}