fix(kmp): getting started code snippet typo (#14261)

Fixes typo

Author: buenaflor

platform-includes/getting-started-config/kotlin.kotlin-multiplatform.mdx

@@ -3,7 +3,7 @@ import io.sentry.kotlin.multiplatform.Sentry
 
 fun initializeSentry() {
   Sentry.init { options ->
-    options.dsn = "___PUBLIC_DSN___"]
+    options.dsn = "___PUBLIC_DSN___"
     // Adds request headers and IP for users, for more info visit:
     // https://docs.sentry.io/platforms/kotlin/guides/kotlin-multiplatform/data-management/data-collected/
     options.sendDefaultPii = true