Enh/add date modified documentation

[Taniya-Das]

Change

Add the last modified date in the documentation footer.

How to Test

Test locally using python -m mkdocs serve.
Note: The changes are pulled from the last git commit.

Checklist

• Tests have been added or updated to reflect the changes, or their absence is explicitly explained.
• Documentation has been added or updated to reflect the changes, or their absence is explicitly explained.
• A self-review has been conducted checking:
  • No unintended changes have been committed.
  • The changes in isolation seem reasonable.
  • Anything that may be odd or unintuitive is provided with a GitHub comment explaining it (but consider if this should not be a code comment or in the documentation instead).
• All CI checks pass before pinging a reviewer, or provide an explanation if they do not.

Related Issues

[PGijsbers]

If possible, can we also add some text? E.g., "Last modified {timestamp}"? Then it is clearer for the user what it means. If that's not possible then I guess this is fine. We can maybe add a post-processing step at a later time.

[Taniya-Das]

If possible, can we also add some text? E.g., "Last modified {timestamp}"? Then it is clearer for the user what it means. If that's not possible then I guess this is fine. We can maybe add a post-processing step at a later time.

To achieve this, we would likely need a custom template override or post-processing step. Since it's not straightforward, and the custom template I tried did not work as expected, I’ll revisit this later.