Fix: tools/eshell: set prompt-regexp to what eshell expects

eshell-prompt-regexp has to be in sync with eshell-prompt-function otherwise
certain eshell behavior will not work properly

For example: eshell-bol

modules/tools/eshell/config.el

@@ -18,6 +18,7 @@
         eshell-buffer-shorthand t
         eshell-kill-processes-on-exit t
         ;; em-prompt
+        eshell-prompt-regexp "^.* λ "
         eshell-prompt-function #'+eshell/prompt
         ;; em-glob
         eshell-glob-case-insensitive t
@@ -50,6 +51,7 @@ redefines its keys every time `eshell-mode' is enabled."
           :i "<tab>" #'eshell-pcomplete
           :i "C-u"   #'eshell-kill-input
           :i "SPC"   #'self-insert-command
+          :i "C-a"    #'eshell-bol
           :m "<return>" #'+eshell/evil-append
           :n [remap evil-window-split]       #'+eshell/split
           :n [remap evil-window-vsplit]      #'+eshell/vsplit