Revert "feat: update citation capitalization (#162)"

This reverts commit 993d173.

Author: gadomski

docs/paper.bib

@@ -34,7 +34,7 @@ @software{Gillies_Shapely_2024
 
 @manual{Cartopy,
 author = {{Met Office}},
-title = {{Cartopy: a cartographic Python library with a Matplotlib interface}},
+title = {{Cartopy: a cartographic python library with a Matplotlib interface}},
 year = {2010 - 2015},
 address = {Exeter, Devon },
 url = {https://scitools.org.uk/cartopy}