• adds yarn 3.6.4 = yarn "berry", and replaces use of npm's package-lock.json with yarn.lock
• adds zipfs yarn sdk integration for vscode, so typescript and prettier reads via yarn's zipfile cache
• avoids yarn zero installs for now (= we're not committing our dependency cache)
• adds root README explaining the yarn setup
• adds github workflow to verify that everything passes typechecking, formatting, linting and tests, yay 🎉 (if we make a github org and move this repo there, e.g. "majiix", and we make us both admins, we can both collab on repo settings)
• ran cargo fmt on all backend code
• ran prettier on all frontend code
• consolidates gitignore in root
• adds backend .env handling, with configurable PORT.
• uses pinned versions in frontend package.json for better control
• extends frontend tsconfig.json with extensive type safety
• consolidates naming everywhere from "maajix" to "majiix" (we could go the other way, I just used the most common - although we should perhaps rename the repo in that case)

(note: all script snippets below start from root of repo)

1. set up ffmpeg

cd ffmpeg
./build.sh
sudo ./install.sh

2. download free creative commons public domain media

cd backend/media
./download.sh

3. run server

cd backend
yarn dev # (or `cargo run`)

4. let server ingest downloaded media, transcoding it to hls - let's pretend this is a user stream instead

curl localhost:8080/ingest

5. serve frontend

cd frontend
yarn dev

6. click the new button, and watch the network tab making several requests over time to fetch the relevant chunks. You can also right click and select "Show All Controls" (Chrome) / "Show Controls" (Firefox + Safari) and try scrubbing to see the relevant chunks adaptively being streamed.