Enhancement: extend hdhomerun widget (#2757)

docs/widgets/services/hdhomerun.md

@@ -5,10 +5,14 @@ description: HDHomerun Widget Configuration
 
 Learn more about [HDHomerun](https://www.silicondust.com/support/downloads/).
 
-Allowed fields: `["channels", "hd"]`.
+Allowed fields: `["channels", "hd", "tunerCount", "channelNumber", "channelNetwork", "signalStrength", "signalQuality", "symbolQuality", "networkRate", "clientIP" ]`.
+
+If more than 4 fields are provided, only the first 4 are displayed.
 
 ```yaml
 widget:
   type: hdhomerun
   url: http://hdhomerun.host.or.ip
+  tuner: 0 # optional - defaults to 0, used for tuner-specific fields
+  fields: ["channels", "hd"] # optional - default fields shown
 ```