Shuffle file names around for prevent CDN caching :/

Author: benjojo

.github/demo.png renamed to .github/demo-new.png

@@ -3,7 +3,7 @@ alertmanager-discord
 
 Give this a webhook (with the DISCORD_WEBHOOK environment variable) and point it as a webhook on alertmanager, and it will post your alerts into a discord channel for you as they trigger:
 
-![](/.github/demo.png)
+![](/.github/demo-new.png)
 
 Example alert manager config: