Use + CONTENT for consistency

Closes #228

Author: HarveyKandola

gui/app/templates/components/folder/documents-list.hbs

@@ -124,7 +124,7 @@
 {{/ui/ui-dialog}}
 
 {{#if showAdd}}
-	{{ui/empty-state icon=constants.Icon.ArrowUp message="Add documents via + DOCUMENT"}}
+	{{ui/empty-state icon=constants.Icon.ArrowUp message="Add documents via + CONTENT"}}
 {{/if}}
 
 {{#if showLockout}}