new 3 Mar 2020 stable release of LAMMPS

HI all - a new stable release of LAMMPS was posted
today. You can get it either via GitHub, SourceForge,
or the tarball on the LAMMPS website.

Here are the new features since the last stable
release in Aug 2019:

https://github.com/lammps/lammps/releases/tag/stable_3Mar2020

Thanks to Axel Kohlmeyer and Richard Berger for
lots of work on upgrading the doc pages for this
release, especially all the math equations.

Steve