Add see-also section to command docs for better discoverability

The command docs are fantastic. I'm a new user and find myself using help foo constantly and learning a ton from the examples. However, discoverability is still an issue for me. When I realize that enter is the way to "pushd", I have no idea that shells is the way to see them (traditional "dirs"). It'd be really helpful if there was some cross-referencing in the help outputs, probably below the Examples: section.

I would be up for trying (a PR) to add a bunch of See also: sections to the commands references (.md). But want to make sure you folks are on board with the idea before putting time into it.

The motivation for this is what's seen in the Clojure docs (similar to how a single web doc resource is exported into editor tooling (cider etc)): https://clojuredocs.org/clojure.core/reduce
The "SEE ALSO" section there near the bottom (and on all the similar docs) is very useful.

Beginne damit, die Befehlsreferenzdateien (.md) zu lokalisieren und zu prüfen, wie die aktuellen Help-Ausgaben ihre Examples-Abschnitte darstellen. Füge unterhalb dieser Beispiele die vereinbarten Querverweise hinzu, wobei die Beziehung zwischen enter und shells als Beispiel dient. Als erledigt gilt die Aufgabe, wenn die relevanten Befehlsdokumentationen durchgängig nützliche See also-Abschnitte enthalten.