Update README.md

Author: stevenjgibbons

setplot_files/README.md

@@ -1,3 +1,11 @@
 This folder contains a sample setplot.py file should you prefer to use the clawpack plotting system.  
 
 All output (fort.*) files must be in a folder _output.  
+
+Typing 
+```
+make plots
+```
+will generate png, tex, and html files and can be animated from within a web-browser.
+
+![Single frame of animation created using unedited setplot.py file.](BingClaw_anim_example.png)