docs: Add Readme

Author: andre-dietrich

README.md

@@ -1,2 +1,100 @@
 # edrys_module-markdown-it
-Markdown interpreter module for edrys
+
+With this module you can define tasks with Markdown-it.
+Additionally it adds support for:
+
+* __Katex:__ `$formula$` or `$$formula$$`
+* __PlantUML:__
+
+  ```` markdown
+  ```plantuml
+  Bob -> Alice : hello
+  ```
+  ````
+
+* __DOT:__
+
+  ```` markdown
+  ```dot
+  digraph example1 {
+    1 -> 2 -> { 4, 5 };
+    1 -> 3 -> { 6, 7 };
+  }
+  ```
+  ````
+
+* __ditaa:__
+
+  ```` markdown
+  ```ditaa
+  +--------+   +-------+    +-------+
+  |        +---+ ditaa +--> |       |
+  |  Text  |   +-------+    |diagram|
+  |Document|   |!magic!|    |       |
+  |     {d}|   |       |    |       |
+  +---+----+   +-------+    +-------+
+      :                         ^
+      |       Lots of work      |
+      +-------------------------+
+  ```
+  ````
+
+Import the following URL to your document:
+
+```
+https://cross-lab-project.github.io/edrys_module-markdown-it/index.html
+```
+
+## Configuration
+
+To simplify the usage, we provide the example in Yaml and not in JSON, you have to convert it by your own.
+Additionally you can modify only the general configuration:
+
+``` yaml
+md: |-
+  # Main Document
+
+  This document will be shown to all users,
+  except if you add additional roles,
+  then this will be used as the fallback.
+
+  Additional html content is also possible
+
+  <iframe
+    width="560"
+    height="315"
+    src="https://www.youtube.com/embed/BdKyq56Cijo"
+    title="YouTube video player"
+    frameborder="0"
+    allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
+    allowfullscreen
+  ></iframe>
+
+  next to formulas: $\frac{12}{x}$
+
+  and next to diagrams:
+
+    ```dot
+  digraph example1 {
+    1 -> 2 -> { 4, 5 };
+    1 -> 3 -> { 6, 7 };
+  }
+
+student: |-
+  # Student documentation
+
+  This content will only be shown to users with the role student.
+  If it does not exist, md is used as fallback.
+
+teacher: |-
+  # Teacher documentation
+
+  This content will only be shown to users with the role teacher.
+  If it does not exist, md is used as fallback.
+
+station: |-
+  # Station documentation
+
+  This content will only be shown to users with the role station.
+  If it does not exist, md is used as fallback.
+```