add --pre option to installation with pip

Author: gdefe

CONTRIBUTING.md

@@ -33,7 +33,7 @@ Have questions or want to discuss your ideas? Join our Slack community to connec
 Install PyC and its dependencies:
 
 ```bash
-pip install pytorch-concepts
+pip install --pre pytorch-concepts
 ```
 
 For development, you may want to install in editable mode:

README.md

@@ -29,7 +29,7 @@ The name of the library stands for both
 You can install <img src="https://raw.githubusercontent.com/pyc-team/pytorch_concepts/refs/heads/master/doc/_static/img/logos/pyc.svg" width="20px"> PyC with core dependencies from [PyPI](https://pypi.org/project/pytorch-concepts/):
 
 ```bash
-pip install pytorch-concepts
+pip install --pre pytorch-concepts
 ```
 
 After installation, you can import it in your Python scripts as:

doc/guides/contributing.rst

@@ -42,7 +42,7 @@ Install PyC and its dependencies:
 
 .. code-block:: bash
 
-   pip install pytorch-concepts
+   pip install --pre pytorch-concepts
 
 For development, you may want to install in editable mode:
 

doc/guides/installation.rst

@@ -8,7 +8,7 @@ You can install PyC with core dependencies from `PyPI <https://pypi.org/project/
 
 .. code-block:: bash
 
-   pip install pytorch-concepts
+   pip install --pre pytorch-concepts
 
 This will install the core library without data-related dependencies (opencv-python, pgmpy, bnlearn, pandas, torchvision, datasets, transformers).
 
@@ -19,7 +19,7 @@ If you plan to use the ``torch_concepts.data`` module, install with the data ext
 
 .. code-block:: bash
 
-   pip install pytorch-concepts[data]
+   pip install --pre pytorch-concepts[data]
 
 This will install all dependencies including those required for data loading and preprocessing.