Issue #26749: Update devguide to include DNF package manager
Issue #26749: Update devguide to include DNF package manager

Patch by Luiz Poleto.

jeff5/jython-devguide,jython/devguide,ezio-melotti/devguide,jeff5/jython-devguide,jeff5/jython-devguide,jython/devguide,jython/devguide