Added TOC.

README.md

 # Engine API Server
 
+<!-- TOC -->
+
+- [Engine API Server](#engine-api-server)
+    - [Overview](#overview)
+    - [Deployment Modes](#deployment-modes)
+        - [Single Deployment](#single-deployment)
+        - [Redundant Deployment](#redundant-deployment)
+            - [Managing Active Engine State](#managing-active-engine-state)
+            - [High Availability Playlog Synchronization](#high-availability-playlog-synchronization)
+    - [Getting started](#getting-started)
+        - [Requirements](#requirements)
+        - [Installation](#installation)
+        - [Configuration](#configuration)
+            - [Engine 1 Node](#engine-1-node)
+            - [Engine 2 Node](#engine-2-node)
+            - [Synchronization Node](#synchronization-node)
+    - [Running the Server](#running-the-server)
+        - [Development](#development)
+        - [Production](#production)
+        - [Running with Systemd](#running-with-systemd)
+        - [Running with Supervisor](#running-with-supervisor)
+        - [Running with Docker](#running-with-docker)
+    - [Using the API](#using-the-api)
+- [About](#about)
+
+<!-- /TOC -->
+
 ## Overview
 
 The Project serves the Engine API and handles state management of multiple [Engine](https://gitlab.servus.at/aura/engine) instances.