* mhchemParser v4.2.2 in Typescript was used as blueprint for this:
* https://github.com/mhchem/mhchemParser
* The mhchemParserPHP component tests can be run locally on a machine with PHP without MediaWiki-Environment with the MMLmhchemTestLocal.php
* For the tests it is probably only necessary to review the json files (Mhchemv4mml.json, Mhchemv4tex.json).
* src/TexVC/MHChem/MhchemParser.php contains the basic functionality, Patterns, StateMachines, Texify functions are located in dedicated classes
* added extracted mhchem commands which have intermediately have been introduced to the
texVC(PHP) grammar
Change-Id: I8cc3d04937b93339e352adc95c85a8a178b8825f
Bug: T329620