Introductory text before a view
Under "Header" select "Add" and choose "Text area" or "Unfiltered text". Then fill in your text in the text area and click "Apply".



You will need to provide content editors access to your view in order to alter it.

Another option would be to create a custom block and to place it above the Main page content block. Then again, you will need to provide access to the content editors to administer blocks.