docs: add doi badge to readme (#468)

Author: korikuzma

README.md

@@ -9,7 +9,7 @@
 
 ## Releases
 
-[![gitHub tag](https://img.shields.io/github/v/tag/ga4gh/vrs-python.svg)](https://github.com/ga4gh/vrs-python/releases) [![pypi](https://img.shields.io/pypi/v/ga4gh.vrs.svg)](https://pypi.org/project/ga4gh.vrs/)
+[![gitHub tag](https://img.shields.io/github/v/tag/ga4gh/vrs-python.svg)](https://github.com/ga4gh/vrs-python/releases) [![pypi](https://img.shields.io/pypi/v/ga4gh.vrs.svg)](https://pypi.org/project/ga4gh.vrs/) [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.14013256.svg)](https://doi.org/10.5281/zenodo.14013256)
 
 ## Development