apacheGH-39504: [Docs] Update footer in main sphinx docs with correct…

… attribution (apache#39505)

* Closes: apache#39504

Lead-authored-by: Joris Van den Bossche <jorisvandenbossche@gmail.com>
Co-authored-by: Alenka Frim <AlenkaF@users.noreply.github.com>
Signed-off-by: AlenkaF <frim.alenka@gmail.com>

docs/source/conf.py

@@ -201,7 +201,12 @@
 
 # General information about the project.
 project = u'Apache Arrow'
-copyright = f'2016-{datetime.datetime.now().year} Apache Software Foundation'
+copyright = (
+    f"2016-{datetime.datetime.now().year} Apache Software Foundation.\n"
+    "Apache Arrow, Arrow, Apache, the Apache feather logo, and the Apache Arrow "
+    "project logo are either registered trademarks or trademarks of The Apache "
+    "Software Foundation in the United States and other countries"
+)
 author = u'Apache Software Foundation'
 
 # The version info for the project you're documenting, acts as replacement for