Improve docco and output formatting

README.md

@@ -1,9 +1,24 @@
 # slicerdicer
 
-Slice and dice an image, turning it into many equal sized tiles.
+Slice and dice an image, turning it into many equal sized tiles. Useful
+for things like leaflet.js, with the Leaflet.Zoomify plugin.
+
+The image is sliced up into equal sized tiles, based on the command line 
+option `--tile-size` (default 512 pixels). 
+
+Once the tiling is finished, the original is resized to half its current
+dimensions (the orignal file on disk is not touched) and the process repeats.
+Each halving is a new "zoom level".
+
+Each file is named something like:
+
+    tile-z-x-y.png
+
+Where 'z' is the zoom level, x and y are the coordinates, with 0,0 being
+the top left tile.
 
 ## Usage
 
-slicerdicer -help
+    slicerdicer --help
 
-slicerdicer --filename foo.png --tile-size 256
+    slicerdicer --filename foo.png --tile-size 256

main.go

@@ -70,7 +70,7 @@ func main() {
       }
     }
 
-    fmt.Println()
+    fmt.Print("\r                                   \r")
     z++
   }