Add a section about philosophy.

30.about/10.contributing/page.en.md

@@ -3,12 +3,22 @@ title: Contributing
 slug: contributing
 ---
 
+## Philosophy
+
+Each course is subject to the licence its original authors chose.
+Translations should probably follow the same licence as the original works.
+
+! @cmeny Drop a line here about the structure with 4 levels.
+
+
 ## How it works
 
+
 - 📖 *Flat files*
   - [enhanced markdown](#enhanced-markdown) for content
   - [YAML frontmatter](https://learn.getgrav.org/15/content/headers) for metadata
 - 🦊 *Continuous integration* using [GitLab (Ruby)](https://m3p2.ljbac.com)
+  - edit courses from your browser, using GitLab's WebIDE
 - 🌎 *Decentralized versioning* using [Git](https://en.wikipedia.org/wiki/Git)
   - asynchronous and offline collaboration
   - scales to thousands of contributors
@@ -17,6 +27,7 @@ slug: contributing
   - vibrant and growing community in 2019
 
 
+
 ## Data Flow
 
 ```mermaid