FuXi integrated into insert_worm.py script

This adds an "infer()" call at the end of the script which adds inferred triples to the worm.db graph.

For now it just adds "MuscleURI" a "TestClass", but we can simply replace the rules and FuXi will infer relevant facts.

Readme updated and demo simplified so it is easier to see what is going on.

Any comments/criticisms much appreciated.