feat(shell/eat): improve eat configuration

This commit enables eat-mode in Eshell, allowing the use of tools that
normally would not work in Eshell.

It also automatically closes the eat buffer when exiting the shell
instead of keeping it open.

docs/emacs/packages/applications.org

@@ -1555,7 +1555,12 @@ for VTerm as I never got VTerm to actually work on NixOS.
                          "*.ti" ("terminfo/e" "terminfo/e/*")
                          ("terminfo/65" "terminfo/65/*")
                          ("integration" "integration/*")
-                         (:exclude ".dir-locals.el" "*-tests.el"))))
+                         (:exclude ".dir-locals.el" "*-tests.el")))
+  :init
+  (add-hook 'eshell-load-hook #'eat-eshell-mode)
+  (eat-eshell-mode 1)
+  :config
+  (add-hook 'eat-exit-hook #'kill-this-buffer))
 #+end_src
 
 *** Shell-pop