docs: Add a "Last updated on:" HTML footer

Show the build time of the docs. Ported from
open-mpi/ompi#13236

Signed-off-by: Ralph Castain <[email protected]>
(cherry picked from commit 866a113)

Author: rhc54

docs/conf.py

@@ -27,7 +27,7 @@
 month = mydate.strftime("%B")
 
 project = 'OpenPMIx'
-copyright = f'2014-{year}, The OpenPMIx Community'
+copyright = f'2014-{year}, OpenPMIx Community'
 author = 'The OpenPMIx Community'
 
 # The full version, including alpha/beta/rc tags
@@ -151,6 +151,9 @@
 # so a file named "default.css" will overwrite the builtin "default.css".
 #html_static_path = ['_static']
 
+# Put a "Last updated on:" timestamp at the bottom of each page.
+html_last_updated_fmt = '%Y-%m-%d %H:%M:%S %Z'
+
 # -- Options for MAN output -------------------------------------------------
 
 import os