Say the date, and name the page, in each site's own languageUnverified

.Date.Format is Go's own formatter, which knows one set of month names
and they are English. So every site but one dated its lead post "April
13, 1990", and its post headers "1990-04-13" - chrome fully translated
around a date that never was. It only became visible now that the other
four languages have a post to date at all.

time.Format is the localized one, but it substitutes names and cannot
reorder: where the day goes, and whether the month is joined with "de"
or a comma or 年, is part of the translation and not of the template. So
the layout string itself moves into i18n/*.toml - dateLong for the home
lead, dateShort for a list entry, dateNumeric for the post header - and
the three call sites ask for it by key.

Those values are Go reference-time layouts, where "January" is a token
and not a word. Renaming it to "janvier" is the obvious thing for a
translator to do and it breaks the date, so each file says so above the
keys.

Two dates deliberately stay as they are. The datetime attribute on
<time> is the machine-readable one and stays ISO 8601, which is the only
thing a parser may assume. The feed's pubDate and lastBuildDate stay
English because RFC 822 requires English day and month names - a
localized one is not a late date, it is an unparseable one, for every
subscriber at once.

/posts/ had no _index.md, so Hugo titled it after the directory and the
heading and the tab read "Posts" in all five. Each language now names it
with the word it already uses for counting them: Articles, Artículos,
投稿. pt keeps "Posts", which is what its own count string says.

Smaller, in fr: "Dernier" reads as the final one, where the label means
the most recent - "Plus récent", which is what pt already said. And the
pt bio takes the <br> the other four have, so the second line starts
where theirs do.

Abbreviated month names are wider than "Apr 13", and the entry date sits
in a fixed 4.25rem column set to nowrap, so it was worth measuring:
widest case is "13 janv." at 66.9px against a 73.69px column, with the
0.85rem gap still behind it. Nothing overflows, and the column stands.