fix(copyright): automate copyright updating for docs (#3708)

Author: JasonGrace2282

docs/source/conf.py

@@ -8,6 +8,7 @@
 
 import os
 import sys
+from datetime import datetime
 from pathlib import Path
 
 import manim
@@ -25,7 +26,7 @@
 # -- Project information -----------------------------------------------------
 
 project = "Manim"
-copyright = "2020-2022, The Manim Community Dev Team"
+copyright = f"2020-{datetime.now().year}, The Manim Community Dev Team"
 author = "The Manim Community Dev Team"