Update steps in installation and also some paths

[IshaanDesai]

Description

This PR modifies the steps for installing the adapter according to the directory structure one would get by following the latest DuMuX installation steps.

Checklist

• I updated the documentation.

[ajaust]

Thanks for the update. It looks good to me overall. I have only very few minor remarks/questions.

I am fine with the change of dunecontrol to ./dune-common/bin/dunecontrol as this is closer to the DuMuX documentation and we ask the user to clone the adapter to the same directory as DuMuX.

Just as a hint as it might be useful: I liked to install DUNE and potentially DuMuX separately from the adapter since I would not change DUNE nor DuMuX on a regular basis. I added $DUNE_PATH/dune-common/bin to the PATH environment variable such that I could use dunecontrol from everywhere. Additionally one can send the environment variable DUNE_CONTROL_PATH such that dunecontrol finds the installed DUNE modules. You can find an example for this in the Dockerfiles that are part of this repository.

[IshaanDesai]

Just as a hint as it might be useful: I liked to install DUNE and potentially DuMuX separately from the adapter since I would not change DUNE nor DuMuX on a regular basis. I added $DUNE_PATH/dune-common/bin to the PATH environment variable such that I could use dunecontrol from everywhere. Additionally one can send the environment variable DUNE_CONTROL_PATH such that dunecontrol finds the installed DUNE modules. You can find an example for this in the Dockerfiles that are part of this repository.

Thanks for the hint, this is useful!