Add last updated date

[timvink]

v.0.3.0 adds our own Git classes, making it possible to also expose the last updated date of a page or entire site.

Markdown tags

We can add the following markdown tags:

• {{ git_page_last_updated }}
• {{ git_site_last_updated }}

These should output the date or datetime only, and not include the text "Last updated: ". That should be picked up in #14.

Jinja2 variables

For those developing custom themes, we can extend the dict {{ git_info }}. Proposal:

{
    ...,
   'page_last_updated' : {
        'date' : '28 November, 2019',
        'datetime' : '28 November, 2019 13:57:28'
   },
    'site_last_updated' : # same structure
}

Options

We should add two new options:

• type: and support two options: date and datetime (see https://github.com/timvink/mkdocs-git-revision-date-localized-plugin#type).
• locale: (see https://github.com/timvink/mkdocs-git-revision-date-localized-plugin#locale)

Other

• Update README
• Update tests
• Update setup.py to include dependency on babel

[timvink]

On second thought, better to use https://github.com/timvink/mkdocs-git-revision-date-localized-plugin