Write project introduction in Readme

[jhohlfeld]

Let's make sure we have a great readme for this project!

Things worth mentioning (from top of my head):

• about NextJS
• how to operate the dev server
• how to get updates rolled out
• about maptiler

How to install

• install bun (https://bun.sh/docs/installation)
• clone repo
• bun install
• .env einrichten
• bun dev

[FelipeLohan]

will help you with your project!

[jhohlfeld]

Hey @FelipeLohan, that's very nice! We didn't plan to take on other contributions at this moment tbh.