Add eshell-z plugin

And replace z alias with it.

modules/emacs/eshell/config.el

@@ -23,7 +23,7 @@ buffer.")
 
 (defvar +eshell-aliases
   '(("q"  "exit")           ; built-in
-    ("z"  "cd =$1")         ; built-in
+    ("z"  "eshell-z $1")    ; `eshell-z'
     ("bd" "eshell-up $1")   ; `eshell-up'
     ("rg" "rg --color=always")
     ("ag" "ag --color=always")
@@ -137,3 +137,9 @@ redefines its keys every time `eshell-mode' is enabled."
 
 (def-package! shrink-path
   :commands shrink-path-file)
+
+
+(after! eshell-z
+  ;; Use zsh's db if it exists, otherwise, store it in `doom-cache-dir'
+  (unless (file-exists-p eshell-z-freq-dir-hash-table-file-name)
+    (setq eshell-z-freq-dir-hash-table-file-name (expand-file-name "z" eshell-directory-name))))

modules/emacs/eshell/packages.el

@@ -2,4 +2,5 @@
 ;;; emacs/eshell/packages.el
 
 (package! eshell-up)
+(package! eshell-z)
 (package! shrink-path)