Update README.md (#94)

Add badge

README.md

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 [![Project Status: Active – The project has reached a stable, usable state and is being actively developed.](https://www.repostatus.org/badges/latest/active.svg)](https://www.repostatus.org/#active)
 [![test](https://github.com/USEPA/harmonize-wq/actions/workflows/test.yml/badge.svg)](https://github.com/USEPA/harmonize-wq/actions/workflows/test.yml)
 [![python version](https://img.shields.io/badge/python-3.8+-blue.svg)](https://www.python.org/downloads/)
+[![pyOpenSci Peer-Reviewed](https://pyopensci.org/badges/peer-reviewed.svg)](https://github.com/pyOpenSci/software-review/issues/157)
 # harmonize-wq
 Standardize, clean, and wrangle Water Quality Portal data into more analytic-ready formats