Barron and Cullen (2022) in markdown

[robbiemorrison]

Here is your recent FOSS publication in markdown. Might be useful to add to the README.txt?

• Barron, Karla Cervantes and Jonathan M Cullen (22 August 2022). "Mat-dp: an open-source python model for analysing material demand projections and their environmental implications, which result from building low-carbon systems". Journal of Open Source Software. 7 (76): 4460. ISSN 2475-9066. doi:10.21105/joss.04460.

Barron, Karla Cervantes and Jonathan M Cullen (22 August 2022).  ["Mat-dp: an open-source python model for analysing material demand projections and their environmental implications, which result from building low-carbon systems"](https://joss.theoj.org/papers/10.21105/joss.04460).  *Journal of Open Source Software*.  **7** (76): 4460.  ISSN [2475-9066](https://www.worldcat.org/issn/2475-9066).  doi:[10.21105/joss.04460](https://doi.org/10.21105/joss.04460).