Update markdown

Author: OptimumCode

Dangerfile.df.kts

@@ -6,8 +6,8 @@ import systems.danger.kotlin.models.github.GitHubIssueLabel
 danger(args) {
   if (git.modifiedFiles.any { it.contains("json-schema-validator/api/") }) {
     markdown(
-      "PR introduces changes to the public API. " +
-        "Please add **\"ABI breaking\"** label if **any line** in API file was changed or deleted. " +
+      "## PR introduces changes to the public API<br/>" +
+        "Please add **\"ABI breaking\"** label if **any line** in API file was changed or deleted.<br/>" +
         "Please add **\"API breaking\"** label if **any public method** in API file was changed or deleted.",
     )
   }