Update citation information in CITATION.cff and README.md

Author: seisman

CITATION.cff

@@ -76,9 +76,9 @@ authors:
   family-names: Wessel
   affiliation: University of Hawaiʻi at Mānoa, USA
   orcid: https://orcid.org/0000-0001-5708-7336
-date-released: 2024-05-01
-doi: 10.5281/zenodo.11062720
+date-released: 2024-09-05
+doi: 10.5281/zenodo.13679420
 license: BSD-3-Clause
 repository-code: https://github.com/GenericMappingTools/pygmt
 type: software
-version: 0.12.0
+version: 0.13.0

README.md

@@ -152,12 +152,12 @@ research using the following BibTeX:
                   Quinn, Jamie and
                   Wessel, Paul},
   title        = {{PyGMT: A Python interface for the Generic Mapping Tools}},
-  month        = may,
+  month        = sep,
   year         = 2024,
   publisher    = {Zenodo},
-  version      = {0.12.0},
-  doi          = {10.5281/zenodo.11062720},
-  url          = {https://doi.org/10.5281/zenodo.11062720}
+  version      = {0.13.0},
+  doi          = {10.5281/zenodo.13679420},
+  url          = {https://doi.org/10.5281/zenodo.13679420}
 }
 ```