Add testing command to README

Author: WardCunningham

README.md

@@ -1,4 +1,11 @@
 # graph
+
 lightweight property graph as javascript module
 
 See User Manual and Public Module. [github](https://wardcunningham.github.io/graph/)
+
+## testing
+
+```
+deno test --allow-read=. --allow-net=ward.dojo.fed.wiki
+```