I cleaned up the mess of the file LayoutMess.blender and I wanted to show you my success, but I don’t know how…
Hello Lucie, welcome to the community 
You can take a screenshot and paste it directly into your posts, or, if you have some image editing software, perhaps crop the image first and then copy/paste it in, or use the upload feature on the composer toolbar.
Hope this helps
See also;
- Forum User Guides : How can I add images to my posts?