Add README for examples

Author: JanLuca

examples/README.md

@@ -0,0 +1,9 @@
+# Examples
+
+In this folder we provide some examples how to use the variPEPS library. The
+examples are provided as
+
+1. The raw Python script which can be just been executed by calling `python3
+   <script>.py` after installation of the `varipeps` package and
+2. A Jupyter notebook file containing a verbose description of the example. To
+   use this version an installation of the `jupyter` package is required.