Add example

Author: andydotxyz

README.md

@@ -2,3 +2,23 @@
 
 A Go library for adding fancy additions to the filesystem.
 This is useful for file managers and other tools that have a graphical representation of a users files and folders.
+
+## Example
+
+### Create an overlay image
+
+This `over` image can be placed over a folder or other item indicating the type of content in a fancy folder.
+
+```go
+over := &canvas.Image{}
+
+if ff, _ := fancyfs.DetailsForFolder(folderURI); ff != nil {
+		if ff.BackgroundURI != nil {
+			over.File = ff.BackgroundURI.Path()
+		}
+		if ff.BackgroundResource != nil {
+			over.Resource = theme.NewColoredResource(ff.BackgroundResource, theme.ColorNameBackground)
+		}
+		s.over.FillMode = ff.BackgroundFill
+	}
+```