chore: add api rtast key

src/main/kotlin/cn/rtast/fancybot/util/file/ConfigManager.kt

@@ -47,4 +47,5 @@ class ConfigManager : JsonFileHandler<Config>("config.json") {
     val cloudflareR2BucketName = config.cloudflareR2BucketName
     val cloudflareR2PublicUrl = config.cloudflareR2PublicUrl
     val apiSpaceKey = config.apiSpaceKey
+    val apiRtastKey = config.apiRtastKey
 }