Add a command line interface to surgeon in the spirit of jq?#40

jq (https://github.com/stedolan/jq) is a powerful command line json parser. I see that surgeon provides a similar function for html. I am aware that there are a few html command line parsers inspired by jq, for example pup (https://github.com/ericchiang/pup), but from what I can see they are less powerful than surgeon. My suggestion is to add a command line interface to surgeon.