It is possible to use a html object in combination with a online-document text or spreadsheet.

If you use Google Docs or Google Sheets you can create/edit the document online via the Google app and in your X5 you can have a html-object with the code given by Google (for the actual document)

Then you can edit the document online and seconds after it can be seen in your X5 page where you show the document.

Hope this is close to what you asked for.

Another way is to locally create a PDF-file and then upload that file to the net.

In X5 you have a page that shows that PDF file.

When you edit the document on your client then you have to save it as PDF and manually upload it to the same location - and then you will see the new document in your X5-project without changing anything in your project.