Chapter numbers in running column header for referencing

[skreutzer]

The print PDF should include chapter numbers in the running column header, and references to other chapters should include the corresponding chapter number, so it becomes easy to navigate back and forth to the referenced chapter without the need to know where which chapter is and without the need to consult the table of contents.

[skreutzer]

It looks like $/en/peeragogy-shell.tex already has more or less the desired feature in the pattern catalog where \section{}s inside the \chapter{} is used, because the default of the memoir document class seems to give both in the running header, the numbered section title as well as the non-numbered chapter title (which is probably good enough). Outside of the pattern catalog, only non-numbered chapter titles end up on left and right pages.

In the preamble, there are lines with \makeevenhead{companion} and \makeoddhead{companion} that define the typesetting of the headers, where the actual header title text gets filled in by \leftmark and \rightmark. These likely need to be re-defined, for example via

\makepsmarks{companion}{%
  \nouppercaseheads%
  \createmark{chapter}{both}{shownumber}{}{.\ }%
}

which looks like it's already doing what's needed, putting marks for each chapter, maybe needing a little bit more spacing instead of simply \ after the dot. In the pattern catalog, the chapter title for the right side gets overwritten by the section title. All of this needs careful checking, also if space runs out for some titles (and then figure out what to do about them), what about the special insertions like the workbook or frontmatter, and finally reflect use of numbered references via the \label{}/\ref{} mechanism. If the approach above doesn't entirely work already, maybe we could introduce another pagestyle, to use one specifically for the pattern catalog and reset to a different one for other places, that define \createmark{} differently for chapters and sections depending on what's needed in the places in question.

[skreutzer]

Might work correctly without adjustment if updated from source.