Update citation to paper

CHANGELOG.md

@@ -9,7 +9,7 @@ Minor OPTIMADE releases are always intended to be backwards-compatible for clien
 Although the majority of features added in this release are optional for servers, there are a couple of mandatory format additions that are discussed below in the notes for implementations.
 We have clarified our approach to versioning explicitly in the specification under [Versioning of this standard](https://github.com/Materials-Consortia/OPTIMADE/blob/v1.2.0/optimade.rst#versioning-of-this-standard).
 
-For a more academic summary of the changes, please see our preprint: [arXiv:2402.00572](https://doi.org/10.48550/arXiv.2402.00572).
+For a more academic summary of the changes, please see our paper: [10.1039/D4DD00039K](https://doi.org/10.1039/D4DD00039K).
 
 In addition to the specification document itself, machine-readable schemas from this repository can now be found hosted at [schemas.optimade.org](https:///schemas.optimade.org), and HTML builds of the specification can be found at [specification.optimade.org](https://specification.optimade.org).
 

README.md

@@ -50,7 +50,7 @@ Alternatively, the software using the file could itself be licensed in a way com
 If you use OPTIMADE to access or host data, we kindly ask that you cite our papers accompanying the version 1.0 and 1.2 releases:
 
 - Andersen *et al*, OPTIMADE, an API for exchanging materials data, *Sci. Data* **8**, 217 (2021) [10.1038/s41597-021-00974-z](https://doi.org/10.1038/s41597-021-00974-z)
-- Evans *et al*, Developments and applications of the OPTIMADE API for materials discovery, design, and data exchange, *arXiv preprint* (2024) [10.48550/arXiv.2402.00572](https://doi.org/10.48550/arXiv.2402.00572)
+- Evans *et al*, Developments and applications of the OPTIMADE API for materials discovery, design, and data exchange, *Digital Discovery* (2024) [10.1039/D4DD00039K](https://doi.org/10.1039/D4DD00039K)
 
 To cite an individual version of the specification, please use the versioned records on Zenodo: