Change API URL in README for WorldCup2026 plugin

Updated the data source URL in the README to point to the new community data source.

Author: TimWheeler-SQUP

plugins/WorldCup2026/v1/docs/README.md

@@ -1,6 +1,6 @@
 # Before you start
 
-This plugin connects to the community API at [worldcup26.ir](https://worldcup26.ir) — an unofficial, community-maintained data source. It is not an official FIFA API. Data coverage and availability depends on the third party keeping the service running.
+This plugin connects to the community data source at https://raw.githubusercontent.com/openfootball/worldcup.json/master/2026/worldcup.json — an unofficial data source. It is not an official FIFA API. Data coverage and availability depends on the third party keeping the service running.
 
 No account, API key, or credentials are required.