Add troubleshooting instructions

[p1gp1g]

Many users do not have a fully configured setup (server-side or the distributor is not logged-in) and complain some app do not work

[p1gp1g]

1. Try UP-Example
   if it works -> Troubleshot the app or ask for help on this app community
2. Trying to use Gotify ? Check twice it is Gotify-UP and not Gotify installed on your phone.
   if it was Gotify -> install Gotify-UP
3. Try with UP-FCM distributor or Gotify-UP with an account on https://gotify1.unifiedpush.org/ (opened to registration)
   if it works -> you have a problem on your setup : If you were trying to self-host Gotify : Have you set the rewrite-proxy ?

[karmanyaahm]

Would it be possible to somehow automate and add checking functionality into UP-Example or make a similar app called UP-Troubleshoot? It probably can't check all possible distributors, but it could check common ones like Gotify.

ie first check if distributor is installed and can send an endpoint
then does the endpoint work
if not, (assuming Gotify) does sending a Gotify type payload to /message instead of /UP work - if so, inform user that proxy is needed
etc etc

[p1gp1g]

The troubleshoot function on UP-Example is a good idea

[p1gp1g]

Done