Merge branch 'add-readme' into 'master'

add readme

See merge request !2

readme.md

+# REST Alternativen
+
+## Starting the apps
+
+The codebase is split up into two applications: `image_server` and `todo_app`. The ToDo app is the primary backend, handling requests from the browser and displaying the frontend, and the image server is a service intended for managing and resizing pictures.
+
+NodeJS v20 is required.
+
+1. To run the image server, execute `docker compose up`.
+2. To run the todo app, execute `cd todo_app; npm i && npm run dev`.
+3. View the frontend on `http://localhost:3000`.