Delete 4-tier-todo-app/Dockerfile

Delete 4-tier-todo-app/app.py

Add SG whatsap invite links

Add 4 tier microservices todo app

Update README.md

Update Code-of-Conduct.md

Update Code-of-Conduct.md

Create Code-of-Conduct.md

add: weekly session resources

add: week2-study session

add: deployment

Merge branch 'main' of https://github.com/colossus06/cka-ckad-study-group-2024

add: trivy operator for security scan

Create test.md

update: collection + helm