Fix discord announcement not including minecraft version (#821)

(cherry picked from commit 5aece82)

build.gradle

@@ -145,7 +145,7 @@ publishMods {
 	discord {
 		webhookUrl = System.getenv("DISCORD_WEBHOOK")
 		username = "Changelog"
-		content = changelog.map { "<@&1134565945482948638>\n## Skyblocker v${mod_version}\n" + it}
+		content = changelog.map { "<@&1134565945482948638>\n## ${displayName}\n" + it}
 	}
 }