Rollup Fix (found @ Stackoverflow)
Important files:
src/firebaseConfig.js Add your Firebase Config here!!!
rollup.config.js Rollup Fix (see post @ stackoverflow)
src/template.html Added firebase CDN
src/client.js Prepares firebase on the Client
src/firebase.js checks if we are on the client or serverside and returns the firestore() function
src/routes/index.svelte show our list on serverside & clientside