Update README.md

README.md

@@ -2,6 +2,8 @@
 
 [![Binder](https://mybinder.org/badge.svg)](https://mybinder.org/v2/gh/o-date/lidar/master)
 
-NB. The final codeblock in both notebooks creates an animated gif; the result will not be displayed in the notebook, but will be available for viewing or downloading from a new folder, 'export', that gets created.
+NB. The final codeblock in both notebooks creates an animated gif from the data. That final codeblock is computationally intensive; it will take some time to run. The results will be written to a new folder called 'export'; you can open that folder by clicking on the jupyter logo at top and then clicking on the 'export' folder.
 
-Start with the Montreal demo notebook.
+You will know the code is finished when the `[*]` at the left of the code block changes to a number.
+
+Start with the Montreal demo notebook. It contains some code that the Avebury notebook depends on.