[GRASS-git] [OSGeo/grass] e81764: Add a Gitter chat badge to README.md (#2540)

[The Gitter Badger]

  Branch: refs/heads/main
  Home:   https://github.com/OSGeo/grass
  Commit: e8176433c83b341a76d0c970b8399edd8c8a4026
      https://github.com/OSGeo/grass/commit/e8176433c83b341a76d0c970b8399edd8c8a4026
  Author: The Gitter Badger <badger at gitter.im>
  Date:   2022-08-27 (Sat, 27 Aug 2022)

  Changed paths:
    M README.md

  Log Message:
  -----------
  Add a Gitter chat badge to README.md (#2540)

* Add Gitter badge