Update index.html

index.html

@@ -28,7 +28,9 @@ <h2>Prerequisites for any Undergraduate Computer Science Degree</h2>
   <ul>
     <li><b><a style="text-decoration:none" href="https://missing.csail.mit.edu/" target="_blank">The Missing Semester of Your CS Education</a></b></li>    
     <li><b><a style="text-decoration:none" href="https://smallsharpsoftwaretools.com/" target="_blank">Small, Sharp Software Tools</a></b></li>
-    <li><b><a style="text-decoration:none" href="https://git-scm.com/book/en/v2" target="_blank">Pro Git</a></b></li>
+    <li><b><a style="text-decoration:none" href="https://www.gnu.org/software/bash/" target="_blank">Bash</a></b></li>
+    <li><b><a style="text-decoration:none" href="https://ex-vi.sourceforge.net/" target="_blank">Vi</a></b></li>
+    <li><b><a style="text-decoration:none" href="https://git-scm.com/" target="_blank">Git</a></b></li>
     <li><b><a style="text-decoration:none" href="https://allendowney.github.io/ThinkPython/" target="_blank">Think Python - How to think like a Computer Scientist</a></b></li>   
     <li><b><a style="text-decoration:none" href="https://www.cc4e.com/" target="_blank">C Programming for Everybody</a></b></li>    
     <li><b><a style="text-decoration:none" href="https://lambertk.academic.wlu.edu/breezypythongui/" target="_blank">Breezy Python UI</a></b></li>