Fix non-rendering Zenodo DOI badge

The old zenodo.org/badge/<repo_id>.svg endpoint now 302-redirects (as
text/html), which GitHub's image proxy won't follow, so the badge broke.
Point at the direct concept-DOI badge SVG (10.5281/zenodo.5975552, all
versions) and link to the DOI, both of which resolve with HTTP 200.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: MarcusMNoack

README.md

@@ -6,7 +6,7 @@
 [![Codecov](https://img.shields.io/codecov/c/github/lbl-camera/gpCAM)](https://app.codecov.io/gh/lbl-camera/gpCAM)
 [![PyPI - License](https://img.shields.io/badge/license-GPL%20v3-lightgrey)](https://pypi.org/project/gpcam/)
 [<img src="https://img.shields.io/badge/slack-@gpCAM-purple.svg?logo=slack">](https://gpCAM.slack.com/)
-[![DOI](https://zenodo.org/badge/434768487.svg)](https://zenodo.org/badge/latestdoi/434768487)
+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.5975552.svg)](https://doi.org/10.5281/zenodo.5975552)
 [![Pepy Total Downloads](https://img.shields.io/pepy/dt/gpcam)](https://pepy.tech/project/gpcam)
 [![Downloads](https://static.pepy.tech/badge/gpcam/month)](https://pepy.tech/project/gpcam)