automatic 'end' year of copyright (pandas-dev#31085)

Author: ShaharNaveh

doc/source/conf.py

@@ -10,6 +10,7 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
+from datetime import datetime
 import importlib
 import inspect
 import logging
@@ -137,7 +138,7 @@
 
 # General information about the project.
 project = "pandas"
-copyright = "2008-2020, the pandas development team"
+copyright = f"2008-{datetime.now().year}, the pandas development team"
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the