DOC: Update citation file with JOSS paper reference (#496)

Author: Lucia-Fonseca

CITATION.rst

@@ -1,13 +1,27 @@
+Citation Guidelines
+===================
+
+|JOSS| |Zenodo|
+
+
 If you use SkyPy for work or research presented in a publication (whether
-directly, or as a dependency to another package) we recommend and encourage
+directly, or as a dependency of another package) we recommend and encourage
 the following acknowledgment:
 
   This research made use of SkyPy, a Python package for forward modeling
-  astronomical surveys (SkyPy Collaboration, 2020).
+  astronomical surveys (Amara et. al., 2021, SkyPy Collaboration, 202x).
+
+where the citations are to our publication in the `Journal of Open Source
+Software`_ and the `Zenodo DOI`_ for the specific version of the software that
+you used. We also encourage citations within the main text wherever
+appropriate. DOIs and BibTeX keys are available through the links above.
+
+.. _Journal of Open Source Software: https://joss.theoj.org/papers/10.21105/joss.03056
+.. _Zenodo DOI: https://zenodo.org/record/3755531
+
 
-where (SkyPy Collaboration, 2020) is a citation to the software DOI for the
-specific version that you used. We also encourage you to cite the software DOI
-in the main text wherever appropriate. DOIs and BibTeX keys for each release
-can be found on Zenodo_.
+.. |JOSS| image:: https://joss.theoj.org/papers/10.21105/joss.03056/status.svg
+    :target: https://doi.org/10.21105/joss.03056
 
-.. _Zenodo: https://zenodo.org/record/3755531
+.. |Zenodo| image:: https://zenodo.org/badge/doi/10.5281/zenodo.4475347.svg
+    :target: https://doi.org/10.5281/zenodo.3755531

docs/index.rst

@@ -11,8 +11,9 @@ intention the simulations can then be compared to data as part of an inference
 pipeline.
 
 .. Important:: If you use SkyPy for work presented in a publication or talk
-   please help the project via proper `citation or acknowledgement
-   <https://github.com/skypyproject/skypy/blob/main/CITATION.rst>`_.
+   please follow our :doc:`project/citation`.
+
+
 
 .. _getting-started:
 
@@ -74,6 +75,7 @@ Project details
    :maxdepth: 1
 
    project/code_of_conduct
+   project/citation
 
 
 *****

docs/project/citation.rst

@@ -0,0 +1 @@
+.. include:: ../../CITATION.rst