For accounts where Markdown is the default editor, all standard documentation is created using the Markdown editor. In the API documentation module, except for the endpoints section, all other articles are also in Markdown—except for the first Introduction article, which is auto-generated in the WYSIWYG editor. As a result, when XML content is added to the Introduction page, it doesn't render correctly. Converting the Introduction article to Markdown (for projects which have Markdown as their default editor) will resolve this issue and allow the XML to display as intended.