Is there a way to export all notes from a project with the attached files, like photos, pdf files and audio to a single file, like HTML or PDF depending on the note and files attached to it?
You can export as PDF, and you will see the images in the PDF, but the original files are not there.
If you export in our Agenda Archive format, you end up with a file that is actually a zip. If you change the .agenda extension to .zip, you can unzip it and in there are all the attached files.
Another format that has the original attachments is RTFD. Use the Rich Text with Attachments to get this exported.