Change read-this-file to autofill with the current filename.

configs/init-functions.el

@@ -88,7 +88,9 @@ If PROJECT is not specified, assume current project root."
 ;; Renombrar el archivo actual
 (defun rename-this-file (new-name)
   "Renames both current buffer and file it's visiting to NEW-NAME."
-  (interactive "sNew name: ")
+  (interactive (list (read-string "New name: "
+                                  (file-name-nondirectory
+                                   (buffer-file-name)))))
   (let ((name (buffer-name))
         (filename (buffer-file-name)))
     (unless filename