removed links to vi references due to errors

tutorial/00.bash.ipynb

@@ -362,24 +362,6 @@
     "\n"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "[\n",
-    "[ref0](http://mmlab.snu.ac.kr/courses/2008_winter_comp/lectures/comp_prac_081229.pdf)\n",
-    ", [ref1](http://www.hackerschool.org/Sub_Html/HS_Community/includes/View_Lecture.html?num=05&groups=HS_Middle)\n",
-    ", [ref2](https://alvinalexander.com/blog/post/linux-unix/how-auto-complete-word-vi-vim-editor)\n",
-    ", [ref3](https://www.cs.oberlin.edu/~kuperman/help/vim/windows.html)\n",
-    ", [ref4](https://kb.iu.edu/d/afcx)\n",
-    ", [ref5](https://vim.fandom.com/wiki/Learn_to_use_help)\n",
-    ", [ref6](http://www.viemu.com/a_vi_vim_graphical_cheat_sheet_tutorial.html)\n",
-    ", [ref7](https://superuser.com/questions/486532/how-to-open-files-in-vertically-horizontal-split-windows-in-vim-from-the-command)\n",
-    ", [ref8](https://realpython.com/vim-and-python-a-match-made-in-heaven/)\n",
-    "]\n",
-    "\n"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},