Fix launcher.md (#1075)

Adding a new line to escape between heading and codeblock. However, it
is a hotfix and I will work on a permanent solution on
https://github.com/huggingface/doc-builder

docs/source/basic_tutorials/launcher.md

 # Text-generation-launcher arguments
+
 ```
 Text Generation Launcher
 

update_doc.py

@@ -11,7 +11,7 @@ def main():
     output = subprocess.check_output(["text-generation-launcher", "--help"]).decode(
         "utf-8"
     )
-    final_doc = f"# Text-generation-launcher arguments\n```\n{output}\n```"
+    final_doc = f"# Text-generation-launcher arguments\n\n```\n{output}\n```"
 
     filename = "docs/source/basic_tutorials/launcher.md"
     if args.check: