Add ChanceIndex oEmbed provider (#921)

* Add ChanceIndex oEmbed provider

* Fix ChanceIndex provider: YAML list format + live example_url

Author: nechehin

providers/chanceindex.yml

@@ -0,0 +1,11 @@
+---
+- provider_name: ChanceIndex
+  provider_url: https://chanceindex.com
+  endpoints:
+    - schemes:
+        - https://chanceindex.com/odds/*
+      url: https://chanceindex.com/api/oembed
+      example_urls:
+        - https://chanceindex.com/api/oembed?url=https%3A%2F%2Fchanceindex.com%2Fodds%2Fputin-out-before-2027
+      discovery: true
+...