Taxonomies and series

[Enrico Zini]

(from a conversation with @DonKult)

In the example you have a dropdown menu which is nice, but I would like
to link to a page showing all entries of the series, which is the page
of the associated tag, but reaching that seems hard:
url_for(taxonomy('tags').categories[page.meta.series])
I was kinda hoping for url_for(page.meta.series_tag) especially if
– not that I have tried – you have multiple taxonomies with series's…

If the series is autogenerated from a tag, indeed a way to generate a
link to the tag page would be enough. If the series is not
autogenerated from a tag, we currently wouldn't have a recap page for
the series.

For the first case, the series feature could easily add a metadata to
the page pointing to the series tag.

For the second case, I'm thinking of mandating that series have to be
tags. One can always create a 'series' taxonomy, if one doesn't want to
add some series to the normal set of tags. This would also automatically
provide each series with an RSS feed, and maybe simplify some of the
series code, by just using tags code to track which pages belong to a
series.

TL;DR: merge series and taxonomies, mandating the fact that a series is an entry in a taxonomy.

The series header can be used to both add a tag and state that it is used as a series.

Document that if one doesn't want to mix series in one's own tag, one can create a new taxonomy for series. That would also give an index pages to all the series in a website.