template: compare lastmod and publishdate

Most of blog posts have the lastmod displayed even if the publishdate is
the same day, because lastmod comes from git information and has also
hour, minutes and second, and publishdate is set manually, with only
year, month and day.

* Formats the date to compare them accurately, with datFormat function.
* Styles a little bit the blockquote tag.
* Spaces evenly the post information blocks.
* Closes #5

Co-Authored-by: Igor Milhit <igor@milhit.ch>