(Emacs/config|elisp)~rework Eshell

Now I have separate modules for the additional new functions I
introduced for eshell and for the prompt function I made.  Cleans up
the configuration a bit and makes it easier to examine those files on
their own, which I expect to grow.

Emacs/.config/emacs/.config/eshell/aliases

@@ -5,4 +5,4 @@ alias gs magit-status
 alias clear clear-scrollback
 alias d dired-other-window $1
 alias gt goto
-alias p~ project-root
+alias pr project-root