Add online links

README.md

@@ -9,6 +9,9 @@ by [Finn Voichick](https://orcid.org/0000-0002-1913-4178),
 [Michael Hicks](https://orcid.org/0000-0002-2759-9223). The code in this
 repository was written by Finn and Liyi, supervised by Robert and Mike, with
 some advice from [Leonidas Lampropoulos](https://orcid.org/0000-0003-0269-9815).
+It is available online at
+[gitlab.umiacs.umd.edu/finn/qunity](https://gitlab.umiacs.umd.edu/finn/qunity)
+and [doi:10.5281/zenodo.7150282](https://doi.org/10.5281/zenodo.7150282)
 
 The Coq code in this repository formally defines the Qunity language, including
 a typechecker. The soundness of the typechecker has been formally verified.