added comments to ammonia example
added comments to ammonia example

keflavich/pyspeckit,dinossimpson/pyspeckit,vlas-sokolov/pyspeckit,jpinedaf/pyspeckit,bsipocz/pyspeckit,keflavich/pyspeckit,dinossimpson/pyspeckit,e-koch/pyspeckit,allisony/pyspeckit,vlas-sokolov/pyspeckit,pyspeckit/pyspeckit,jpinedaf/pyspeckit,mikelum/pyspeckit,e-koch/pyspeckit,low-sky/pyspeckit,low-sky/pyspeckit,keflavich/pyspeckit-obsolete,bsipocz/pyspeckit,mikelum/pyspeckit,pyspeckit/pyspeckit,allisony/pyspeckit