Add documentation on the new pre-commit hook

docs/text/how_to_contribute.rst

@@ -39,47 +39,56 @@ Further, there are some technical decisions we made:
     6. Clear the Output of iPython notebooks. This improves the readability of related Git diffs.
 
 
-Test framework
-''''''''''''''
-
-After making your changes, you probably want to test your changes locally. To run our comprehensive suite of unit tests
-you have to install all the relevant python packages with
+Installation
+''''''''''''
 
+Install all the relevant python packages with
 
 .. code::
 
     cd /path/to/tsfresh
     pip install -r requirements.txt
     pip install -r rdocs-requirements.txt
     pip install -r test-requirements.txt
+    pre-commit install
     pip install -e .
 
 
 The last command will dynamically link the tsfresh package which means that changes to the code will directly show up
 for example in your test run.
 
-Then, if you have everything installed, you can run the tests with
+
+Test framework
+''''''''''''''
+
+After making your changes, you probably want to test your changes locally. To run our comprehensive suite of unit tests
+you have to:
 
 
 .. code::
 
     pytest tests/
 
 
-or build the documentation with
+Documentation
+'''''''''''''
+
+Build the documentation after installing as described above with
 
 
 .. code::
 
     python setup.py docs
 
 
-
 The finished documentation can be found in the docs/_build/html folder.
 
-On Github we use a Travis CI Folder that runs our test suite every time a commit or pull request is sent. The
-configuration of Travis is controlled by the
-`.travis.yml <https://github.com/blue-yonder/tsfresh/blob/main/.travis.yml>`_ file.
+
+Styling
+'''''''
+
+We use black and isort for styling. They are automatically triggered on every commit after having installed pre-commit
+(as described above).
 
 
 We are looking forward to hear from you! =)