[doc] add how-to-install info]

README.md

 # r2ogs6
 
-An R-API to the multiphysics simulator OpenGeoSys-6 that allows preprocessing (preparing input files), execute simulation runs, retrieve and post-process output data in R. 
\ No newline at end of file
+An *r2ogs6* is an R-API to the multiphysics simulator [OpenGeoSys 6](https://gitlab.opengeosys.org/ogs/ogs).
+*r2ogs6* allows to preprocess (preparing input files), execute simulation runs, retrieve, post-process and visualize output data in R.
+Furthermore, the package comes with functionality to define [ensemble runs](vignettes/ensemble_workflow_vignette.Rmd)
+
+## Install *r2ogs6*
+
+### Set-Up your Environment
+
+Apart from having the library installed and loaded, there are two more prerequisites that need to be met for you to be able to use `r2ogs6` to its full extent.
+
+The most important one is having OpenGeoSys 6 installed on your system. You can download the current version of OpenGeoSys 6 from [here](https://www.opengeosys.org/releases/). 
+
+Secondly, to read in the `.vtu` and `.pvd` files produced by OpenGeoSys 6, you need a Python installation including the libraries `numpy` and `vtk`. If you have an Anaconda installation on your system, setting up a Python environment with `numpy` and `vtk` will work. *r2ogs6* was tested with the following environment.
+
+```
+$ conda create -n r2ogs6 python=3.7
+$ conda install -c anaconda numpy, vtk==8.2.0
+```
+
+If you don't have any Python installation on your system, you can download the latest release of Python from [here](https://www.python.org/downloads/). Instructions on how to install `numpy` and `vtk` can be found [here](https://numpy.org/install/) and  [here](https://pypi.org/project/vtk/).
+
+
+### Install the *r2ogs6* Package
+
+Just clone the repository to your local machine `git clone https://gitlab.opengeosys.org/ag-hydinf/boog-group/r2ogs6.git`
+Open *R* from your local (anaconda) environment.
+For installing *r2ogs6* you need the R-package `devtools`.
+If you do not have `devtools` installed, install it via `install.packages("devtools")`.
+Install *r2ogs6* with `devtools::install("path/to/r2ogs6")` referring to the path of the cloned repository.
+All R-dependencies will be installed if not present.
+
+## Use *r2ogs6*
+
+Just have a look to the vignettes showing:
+
+* [basic features](vignettes/user_workflow_vignette.Rmd) 
+* [creating ensemble runs](vignettes/ensemble_workflow_vignette.Rmd)
+* [further development](vignettes/dev_workflow_vignette.Rmd)
+
+## Links
+
+* [OpenGeoSys Project](https://www.opengeosys.org/)
+* [OpenGeoSys source code](https://gitlab.opengeosys.org/ogs/ogs)
+* [OpenGeoSys documentation](https://www.opengeosys.org/docs/)
\ No newline at end of file

vignettes/user_workflow_vignette.Rmd

@@ -22,12 +22,7 @@ library(r2ogs6)
 ```
 
 ## Prerequisites
-Apart from having the library itself loaded, there are two more prerequisites that need to be met for you to be able to use `r2ogs6` to its full extent.
 
-The most important one is having OpenGeoSys 6 installed on your system. You can download the current version of OpenGeoSys 6 from [here](https://www.opengeosys.org/releases/). 
-
-Secondly, to read in the `.vtu` and `.pvd` files produced by OpenGeoSys 6, you need a Python installation including the library `vtk`. If you have an Anaconda installation on your system, setting up a Python environment with `vtk` will work. If you don't have any Python installation on your system, you can download the latest release of Python from [here](https://www.python.org/downloads/). Instructions on how to install `vtk` can be found [here](https://pypi.org/project/vtk/).
- 
 After loading `r2ogs6`, we can set the package options so it knows where to look for OpenGeoSys 6 and Python.
 
 ```r