Tweak README. Make it clear what "install" means, and avoid a misunderstanding.

Avoid misunderstanding that "comportexviz" needs to be a subfolder of "comportex". Make it clear that this jar is retrieved from "~/.m2", not from "../target". Some of us have been coddled by Clojars and don't know these things :)
Merge pull request #3 from mrcslws/master

Tweak README. Make it clear what "install" means, avoid a misunderstanding.