Update copyright template (jupyterlab#925)

* Update copyright template

Set it to automatically update the end year for the copyright footer in `readthedocs`.

* Update docs/source/conf.py

Used en dash instead of hyphen

Co-authored-by: Jason Weill <93281816+JasonWeill@users.noreply.github.com>

---------

Co-authored-by: Jason Weill <93281816+JasonWeill@users.noreply.github.com>

docs/source/conf.py

@@ -6,8 +6,10 @@
 # -- Project information -----------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
 
+import time
+
 project = "Jupyter AI"
-copyright = "2023, Project Jupyter"
+copyright = f"2023–{time.localtime().tm_year}, Project Jupyter"
 author = "Project Jupyter"
 
 # -- General configuration ---------------------------------------------------