feat: add shellscript

[justchokingaround]

feel free to reject this, if you feel like it doesn't exactly fit the tutorial theme, i just thought i could share some of my knowledge with people who would be interested in web scraping using shell commands

[Blatzar]

Sorry for late review :pensive:

[justchokingaround]

np bbg, anw i'll implement the rest of the feedback later today

[justchokingaround]

want me to change the mega link for the mac firefox build to the one in https://github.com/Blatzar/scraping-tutorial/issues/6 ? (the old one has expired)

[Blatzar]

:people_hugging: thank you