Update website copyright text per Linux Foundation guidance. (#19480)

See https://lfprojects.org/.

Signed-off-by: Scott Todd <scott.todd0@gmail.com>
diff --git a/docs/website/mkdocs.yml b/docs/website/mkdocs.yml
index e436830..6edef7a 100644
--- a/docs/website/mkdocs.yml
+++ b/docs/website/mkdocs.yml
@@ -82,7 +82,10 @@
   assets/images/README.md
   **/snippets/*.md
 
-copyright: Copyright &copy; 2024 The IREE Authors
+copyright: |
+  Copyright &copy; 2024 IREE a Series of LF Projects, LLC.
+  For web site terms of use, trademark policy and other project policies please
+  see <a href="https://lfprojects.org">https://lfprojects.org</a>.
 
 markdown_extensions:
   - abbr