[GRASS-git] [OSGeo/grass] 8d8fe1: Add Zenodo DOI badge to readme (#2122)

[Vaclav Petras]

  Branch: refs/heads/main
  Home:   https://github.com/OSGeo/grass
  Commit: 8d8fe18da2cf3a5280ac1030f35b851a2bd0e6b2
      https://github.com/OSGeo/grass/commit/8d8fe18da2cf3a5280ac1030f35b851a2bd0e6b2
  Author: Vaclav Petras <wenzeslaus at gmail.com>
  Date:   2022-01-24 (Mon, 24 Jan 2022)

  Changed paths:
    M README.md

  Log Message:
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  Add Zenodo DOI badge to readme (#2122)

This adds a badge which shows the DOI from Zenodo. The DOI used is the "cite all versions" DOI which redirects to the latest version on Zenodo.

An alternative would be a badge (also provided by Zenodo) which shows the latest version, but this seems to be more misleading as it would show, for example, whatever is the latest release in the readme file for the main branch. The "cite all versions" DOI at least shows the version-neutral DOI, although it leads to the latest version on Zenodo (which is the latest release in terms of time).