Add a build script to create jargone.js from jargonfile.txt

It is going to be difficult to dynamically load the jargonfile.txt when the bookmarklet is run. The reason for that is if you inject javascript into http://example.com/ and then try to load a file http://mydomain.com/jargonfile.txt, you are going to be blocked (at least by Github) due to their SameOrigin policy.

This PR is a compromise. Given the two halves of the javascript and the plain text jargonfile, it will build a jargone.sh which can then be committed to github.