Add the setup guide for Docker & updated the dockerfile and docker-compose.yml file.

documentation/installation_docker.md

@@ -0,0 +1,57 @@
+### Setup Instructions for Axium within Docker
+
+This guide walks you through building **Axium** as a docker container.
+
+Make sure that you have docker aswell as docker compose (which is bundled with docker in the most recent releases of docker) installed.
+
+Please note! That in a production system I wouldn't want to run the database on the same server as the API.
+
+The shown commands except nano will work on Windows' PowerShell (you can use notepad.exe instead of nano).
+
+---
+
+1. **Clone the Axium repository**:
+   Clone the Axium repository from GitHub:
+   ```sh
+   git clone https://github.com/Riktastic/Axium.git
+   ```
+
+---
+
+2. **Navigate to the Axium directory**:
+   Move into the cloned repository:
+   ```sh
+   cd Axium
+   ```
+
+---
+
+3. **Copy the Example environment file**:
+   Copy the `.env.example` file to `.env` to configure your environment:
+   ```sh
+   cp .env.example .env
+   ```
+
+---
+
+4. **Edit the `.env` File**:
+   Update the `.env` file with your database settings if necessary:
+   ```sh
+   nano .env
+   ```
+
+---
+
+1. **Build and run the container**:
+   Start Axium using Docker Compose:
+   ```sh
+   docker compose up
+   ```
+
+---
+
+After sucessfully building the image, it will start two containers:
+- axium-axium-1: Axium,
+- axium-db-1: The PostgreSQL database
+
+The database will store its files within the `./docker` folder.