Added citation section

README.md

@@ -24,6 +24,11 @@ The BigStitcher plugin must be installed in Fiji. Please follow the instructions
 ## Seeking help or contributing
 We are always happy to help users of our tools, and welcome any contributions. If you would like to get in contact with us for any reason, please see the [contact page of our website](https://brainglobe.info/contact.html).
 
+## Citation
+If you find this package useful, please make sure to cite the original BigStitcher publication:
+> Hörl, D., Rojas Rusak, F., Preusser, F. *et al.* BigStitcher: reconstructing high-resolution image datasets of cleared and expanded samples. Nat Methods 16, 870–874 (2019). https://doi.org/10.1038/s41592-019-0501-0
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 ## License
 Distributed under the terms of the [BSD-3] license,
 "brainglobe-stitch" is free and open source software