[README] add description on installing the package via the master branch

README.md

@@ -21,10 +21,17 @@ To create and activate the virtual environment run the following command in the
 ```
 You can replace `bayes_env` with your preferred name. For more information on virtual environments see [this link](https://packaging.python.org/en/latest/guides/installing-using-pip-and-virtual-environments/).
 
-Now, you can install my project with pip inside the venv with:
+Now, you can install the latest release of the package on PyPI inside the venv with:
 ```bash
   pip install bayesvalidrox
 ```
+and installing the version on the master branch can be done by cloning this repo and installing:
+```bash
+  git clone https://git.iws.uni-stuttgart.de/inversemodeling/bayesvalidrox.git
+  cd bayesvalidrox
+  pip install .
+```
+
 ## Features
 * Surrogate modeling with Polynomial Chaos Expansion
 * Global sensitivity analysis using Sobol Indices