[add] disc 4 solutions

_modules/week-05.md

@@ -9,6 +9,8 @@ Tue Feb 18
 : **Discussion 4**{: .label .label-disc } [Regex, Visualization, and Transformation](https://drive.google.com/file/d/17qU-mPNc3Bw6c3spPmTptMu4w2iRQVJh/view?usp=sharing){:target="_blank"}
     : [Mini-Lecture](https://youtu.be/r7lxybfJK5c){:target="_blank"}, 
     [Notebook](https://data100.datahub.berkeley.edu/hub/user-redirect/git-pull?repo=https%3A%2F%2Fgithub.com%2FDS-100%2Fsp25-student&branch=main&urlpath=lab%2Ftree%2Fsp25-student%2Fdisc%2Fdisc04%2Fdisc04_coding_exercises-blank.ipynb){:target="_blank"},
+    [Solution](https://drive.google.com/file/d/1b0Q3MOGFEjnwr9pkCyAEOAmZB0JLFZnO/view?usp=sharing){:target="_blank"},
+    [Notebook Solution](https://data100.datahub.berkeley.edu/hub/user-redirect/git-pull?repo=https%3A%2F%2Fgithub.com%2FDS-100%2Fsp25-student&branch=main&urlpath=tree%2Fsp25-student%2Fdisc%2Fdisc04%2Fdisc04_coding_exercises_gsi.ipynb){:target="_blank"},
     [Walkthrough](https://youtu.be/jlvkz8Y-zSQ){:target="_blank"}
 
 Thu Feb 20