chore: add introduction

docs/introduction/README.md

@@ -0,0 +1,37 @@
+# Introduction
+
+**discue.io** is a secure and reliable service that enables event-driven communication. It was designed and built from the ground up to support elastic workloads.
+
+It is built solely upon standards and protocols.
+
+## Components
+The main components of **discue.io** are:
+
+- Queues: `secure and persistent storage`
+- Broadcasts: `functions that publish messages to registered listeners`
+- Listeners: `endpoints in your applications that received broadcasted messages`
+- Messages: `strings that will eventually be transmitted to all registered listeners`
+
+**Queues** receive and store event **messages**. Each successfully stored message triggers a **broadcast**. A **broadcast** looks up **listeners** that are registered for the target **queue** and forwards the **message**. 
+
+**Listeners** must be registered for one or multiple **queues** to receive broadcasted **messages**.
+
+**Messages** are simple JSON Objects that contain a string property with name `data`. The value of `data` will eventually be sent to all **Listeners**
+
+## How you can benefit from our service
+Let's say we operate an e-commerce service that sells and ships books to customers. We want to be as open and transparent as possible. After a customer has completed an order, we want them to receive an email notification whenever the status of an order changed. The following status are defined:
+
+- Order received
+- Payment successful
+- Order shipped
+- Order received
+
+Additionally we want to send an notification if an item is out of stock, or the payment failed. All status changes must also be shown in the customer dashboard.
+
+Your development team is split into various pizza teams to allow independent feature development and deployment. 
+
+❌ **Without** event-driven communication the dashboard team would have to source data from the payment and shipment teams whenever a customer opens the dashboard page. That is not only slow but also error-prone. The dashboard probably won't work whenever data can't be gathered from the payment, or the shipment team. 
+
+✔ **With event-driven communication, each team merely publishes events to the event broker**. The **event-broker** then takes care that all **messages** are published to all consumers that are interested in this event. In this scenario your teams only need to know about the **event-broker**. They **don't** have to know about other teams that might or might not need their data.
+
+## Why not ..