DOC: update documentation

doc/concepts.rst

@@ -2,5 +2,7 @@
 The concepts of pycaosdb
 ========================
 
-Some text...
+.. toctree::
+
+   Table structure <table_structure>
 

doc/getting_started.md

-# Getting started with pycaosdb #
-
-1. Install
-2. import
-3. enjoy

doc/index.rst

@@ -9,12 +9,11 @@ Welcome to documentation of CaosDB's MySQL Backend!
 
    Getting started <README_SETUP>
    Concepts <concepts>
-   tutorials
    Maintenance 
    API documentation<functions>
 
 This documentation helps you to :doc:`get started<README_SETUP>`, explains the most important
-:doc:`concepts<concepts>` and offers a range of :doc:`tutorials<tutorials>`.
+:doc:`concepts<concepts>` .
 
 
 Indices and tables