update readme

[Shibu778]

To install everything the created conda environment, the conda environment needs to be activated. I have added conda activate py4vasp-env line in the installation step.

I faced error while installing mdtraj using conda install -c conda-forge mdtraj. However, it is resolved by using conda install conda-forge::mdtraj which I think is the new way of getting mdtraj from conda-forge. I have updated the command to install mdtraj.

[martin-schlipf]

Thank you for your contribution. The missing activate statement is a good catch.

Could you elaborate as to which error you see when you use the conda install -c conda-forge mdtraj command? This command is run by the CI so it would be interesting to know on which OS you use and in case other users report the same issue. In principle, the command you changed this to should have the same functionality, shouldn't it?

[Shibu778]

Indeed, you’re correct. Both commands are equivalent. During my execution of the conda install -c conda-forge mdtraj command, I encountered an HTTP error. However, it was resolved when I ran it again. My apologies for the confusion.” 😊