Update documentation landing page (#376)

Add information about CADET platform to landing page

Author: hannahlanzrath

doc/getting_started/installation_frontend.rst

@@ -27,3 +27,11 @@ To install ``CADET-Python``, open an `conda shell` and execute:
 .. code-block:: bash
 
     pip install CADET-Python 
+
+
+Additional Resources
+^^^^^^^^^^^^^^^^^^^^
+
+- `CADET-Process documentation <https://cadet-process.readthedocs.io/>`_
+- `CADET-Process Workshop <https://github.com/cadet/CADET-Workshop>`_
+- `CADET-Python Tutorial <https://github.com/cadet/CADET-Python-Tutorial>`_

doc/getting_started/introduction.rst

@@ -22,9 +22,3 @@ CADET-Core developers who might want to test their extensions of the simulator s
    :maxdepth: 1
 
    /../developer_guide/cadet_python
-
-
-.. figure:: tutorials/_images/cadet_architecture_overview.png
-
-
-   Relations between CADET-Core, CADET-Python, and CADET-Process.

doc/index.rst

@@ -45,6 +45,18 @@ Features
 * Flexible and extensible through modular design
 * Works on Windows, Linux, and Mac OS X
 
+CADET Platform
+--------------
+
+CADET-Core is part of `CADET <https://github.com/cadet>`_, a collective platform of software repositories that provide tools for biotechnology process modeling.
+CADET-Core can be used as a standalone simulator by interfacing via HDF5 files. Alternatively, CADET-Python provides a wrapper around an HDF5 file reader and writer, simplifying model configuration. 
+Furthermore, it is the interface for CADET-Process, an universal and user-friendly tool for biotechnology process modeling and evaluation.
+
+For more information on the different packages of the CADET platform, see :ref:`here <getting_started>`.
+
+.. figure:: getting_started/tutorials/_images/cadet_architecture_overview.png
+
+   Relations between CADET-Core, CADET-Python, and CADET-Process.
 
 Installation
 ------------