dev docs: introduction

docs/docs/development.rst

@@ -10,6 +10,13 @@ Jedi Development
     your IDE, look at the `plugin api <plugin-api.html>`_.
 
 
+This page tries to address the fundamental demand for documentation of the
+|jedi| interals. Understanding a dynamic language is a complex task. Especially
+because type inference in Python can be a very recursive task. Therefore |jedi|
+couldn't get rid of complexity. We know that *simple is better than complex*,
+but unfortunately it requires sometimes complex solutions to understand complex
+systems.
+
 
 Core
 ----