Sketch a possible database shape

Just sketching.
Add an image, to learn how to add images
Remove the example image
Merge README.md by removing the last few lines
remove this demo image
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/rektide/snager
Merge branch 'master' of https://github.com/rektide/snager
Add nodeunit and an empty test script
Merge branch 'master' of https://github.com/rektide/snager
Merge branch 'master' of https://github.com/rektide/snager
Merge branch 'master' of https://github.com/Johnicholas/ridesnag