Add badges and links to readme (#2)

We fix the readme to show the status of the project.

README.rst

@@ -1,8 +1,24 @@
 aas-core3.0rc02-testgen
 =======================
 
+.. image:: https://github.com/aas-core-works/aas-core3.0rc02-testgen/actions/workflows/ci.yml/badge.svg
+    :target: https://github.com/aas-core-works/aas-core3.0rc02-testgen/actions/workflows/ci.yml
+    :alt: Continuous integration
+
+.. image:: https://coveralls.io/repos/github/aas-core-works/aas-core3.0rc02-testgen/badge.svg?branch=main
+    :target: https://coveralls.io/github/aas-core-works/aas-core3.0rc02-testgen?branch=main
+    :alt: Test coverage
+
+.. image:: https://badge.fury.io/py/aas-core3.0rc02-testgen.svg
+    :target: https://badge.fury.io/py/aas-core3.0rc02-testgen
+    :alt: PyPI - version
+
+.. image:: https://img.shields.io/pypi/pyversions/aas-core3.0rc02-testgen.svg
+    :alt: PyPI - Python Version
+
+
 This is a bundle of programs to generate test data based on the meta-model V3.0RC02.
 
-Please have a look at the directory `test_data`_ for the generated data.
+Please have a look at the directory `test_data/`_ for the generated data.
 
-.. _test_data: TODO
+.. _test_data/: https://github.com/aas-core-works/aas-core3.0rc02-testgen/tree/main/test_data