feat(alerting): Add ilert alert provider (#1082)

* feat(alerting): Add ilert alert provider

* fix: removed additional endpoint from Readme

* fix: removed newline

Co-authored-by: TwiN <twin@linux.com>

* fix: formatting

* fix: restAPIUrl typo

* fix: removed type field, adjusted tests

---------

Co-authored-by: TwiN <twin@linux.com>

config/config.go

@@ -411,7 +411,8 @@ func validateAlertingConfig(alertingConfig *alerting.Config, endpoints []*endpoi
 		alert.TypeGitea,
 		alert.TypeGoogleChat,
 		alert.TypeGotify,
-		alert.TypeHomeAssistant,
+    alert.TypeHomeAssistant,
+    alert.TypeIlert,
 		alert.TypeIncidentIO,
 		alert.TypeJetBrainsSpace,
 		alert.TypeMatrix,