[$] DCC-EX: open-source model railroading

There's just something about trains-model trains in particular. At Everything Open 2023, PaulAntoine spoke about his experiences with the DCC-EX project, which has a variety ofmodel-railroad automation hardware designs and software tools, all of whichare freely available. There is a long legacy of sharing within the modelrailroading hobby, which continues today in the form of free and open-sourcesoftware for it.