Update Node version shown in Wiki from v12 to v20
### Current Situation

Wiki page 
https://github.com/homebridge/homebridge-config-ui-x/wiki/Homebridge-Service-Command#update-nodejs
shows an example referencing a very old version of node 
`sudo hb-service update-node 12.18.1`


### Proposed Change

Update the example to show a much more current node version: 
`sudo hb-service update-node 20.10.0`

### Additional Context

_No response_