Add a great README

README.md

@@ -1,16 +1,105 @@
-# dev
-The main development repository. Clones all repos as submodules in their respective structure.
+![lea.online logo, cc-? University of Bremen](https://blogs.uni-bremen.de/leaonline/files/2019/03/cropped-header-lea-online-01-3.png)
 
 
-## Getting started
+This is the main repository for documentation and development.
 
-If you need help with submodules, please check out the following resources:
+[Build badge]
+
+
+You will find the following resources in this repository:
+
+* [Introduction to lea.online](#introduction-to-lea.online)
+* [Applications and services overview](#applications-and-services-overview)
+* [Developer documentation](#developer-documentation)
+* [Contribution guidelines](#contribution-guidelines)
+
+## Introduction to lea.online
+
+All about lea.online, why, how, who etc.
+
+## Applications and services overview
+
+This section is explaining the lea.online system from an end-user perspective.
+If you are a looking for a technical documentation, you may look into the [developer documentation](#developer-documentation)
+
+The lea.online system consists of three main platforms with different focus:
+
+- **lea.app** - mobile learning application for functional participants
+- **otu.lea** - desktop diagnostics application for participants
+- **teacher** - desktop course and learning group management for instructors  
+
+### How it works
+
+Participants can obtain access to the lea.online system by either downloading the mobile app (yet to be released) or by
+accessing the websites of the learning or diagnostics application platforms.
+
+They can **anonymously register** with a single account, that is used across the system. The [OAuth2](https://oauth.net/2/)
+workflow ensures that no data is shared without proper authorization.
+
+### lea.app
+
+describe how the lea.app works here
+
+### otu.lea
+
+describe how otu.lea works here
+
+### teacher application
+
+describe how the teacher app works here  
+
+
+## Developer documentation
+
+### Architecture
+
+The lea.online system is a network of applications and services.
+The following graphics is an overview of all involved services and applications:
+
+![lea.online technical architecture](./architecture/level-0-system-overview.svg)
+
+
+### Getting started
+
+Explain how to start now, fast, easy
+
+### Submodules structure
+
+This project does not include any of the `leaonline-*` applications or libraries directly but points to specific commits
+of these repositories using submodules.
+
+This has several reasons:
+
+* There is a single entry point for newcomers
+* There is one main development repository, which installs all related projects in one step
+* The main repo can point to certain states, where the whole application and service system is considered stable.
+  Think of it like a "snapshot" of the system beyond the state of each individual repositories.
+* Contributions can occur on the submodule directories without affecting the "stable" state this repo points to
+* Clear release management across multiple repositories
+
+
+If you need help or want to know how to use submodules, please check out the following resources:
 
 https://git-scm.com/book/en/v2/Git-Tools-Submodules
 
 https://git-scm.com/docs/git-submodule
 
-There is an architectural overview in the [architecture](./architecture) folder, which is a good starting point.
+## Contribution guidelines
+
+Describe how our contribution workflow looks like
 
 ## License
-see the submodules.
+
+This repository and it's resources are [MIT licensed](./LICENSE). However, the submodules contain their own licenses and they may 
+differ from the license of this one.
+
+## Funding
+
+This work is part of the research project "lea.online" (FKN: ????????), funded by the German Federal Ministry of 
+Education and Research (BMBF)
+
+Read more about them at the following websites:
+
+- Blog (German language) - https://blogs.uni-bremen.de/leaonline 
+- University of Bremen - https://www.uni-bremen.de/en.html
+- BMBF - https://www.bmbf.de/en/index.html