CDing into the project root can be accomplished with external tools, e.g.
cd $(git rev-parse --show-toplevel)
cd $(hg root)
cd $(npm root)
Any of which could be aliased. Also, +vterm/toggle and term/toggle
define the PROOT environment variable, so `cd $PROOT` will work too.
On the other hand, CDing to the current file/folder requires that the
shell be made aware of the file/directory of some Emacs state, which is
a little trickier to deal with, so I made that the default behavior for
+term/toggle, +vterm/toggle and +eshell/toggle.
9c842bfad8