DOC: Replace Zenodo badge in README with OSF badge.

README.md

@@ -4,7 +4,7 @@
 [![Stable Docs](https://img.shields.io/badge/docs-stable-blue.svg)](https://algebraicjulia.github.io/Catlab.jl/stable)
 [![Dev Docs](https://img.shields.io/badge/docs-dev-blue.svg)](https://algebraicjulia.github.io/Catlab.jl/dev)
 [![Code Coverage](https://codecov.io/gh/AlgebraicJulia/Catlab.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/AlgebraicJulia/Catlab.jl)
-[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.598366.svg)](https://doi.org/10.5281/zenodo.598366)
+[![DOI](https://img.shields.io/badge/DOI-10.17605%2FOSF.IO%2FHMNFE-blue)](https://doi.org/10.17605/OSF.IO/HMNFE)
 
 Catlab.jl is a framework for applied and computational category theory, written
 in the [Julia](https://julialang.org) language. Catlab provides a programming