added neon and argon to Elements.js in the nitroglycerin repository and made the States of Matter suite pull all atom colors from this file, see https://github.com/phetsims/states-of-matter/issues/50
added neon and argon to Elements.js in the nitroglycerin repository and made the States of Matter suite pull all atom colors from this file, see https://github.com/phetsims/states-of-matter/issues/50

phetsims/nitroglycerin,phetsims/nitroglycerin,phetsims/nitroglycerin