Creating Your First HTML5 Page
If you have not yet altered the Dreamweaver Preferences (see later)
then it is best to create a new page using the File -> New dialog.
Make sure that HTML5 is selected in the DocType drop down list.
Select Blank Page, Page Type: HTML and Layout: None.
If you have an earlier version of Dreamweaver, then you will need
to create an empty HTML5 page manualy and use it as a starting point
each time (by using File -> SaveAs)