support images in briefing and setup theia-full

CHANGELOG.md

Dockerfile

plugins/deadlock-extension/README.md

plugins/deadlock-extension/dev/config/user-challenge.json

plugins/deadlock-extension/dev/docs/briefing.md

plugins/deadlock-extension/dev/docs/toast.jpg

plugins/deadlock-extension/setup-dev-env.sh

plugins/deadlock-extension/src/extension.ts

plugins/deadlock-extension/src/view/briefingView.ts

server.js

start.sh