Move parts of zsh config to bash config

[m-rey]

At the moment, the bash config (.bashrc) sources the zsh config. However, some of the things in the zsh config are not compatible with bash. Thus simply sourcing things raises errors.

Therefore, for compatibility, "general" things could be moved to the bash config, zsh specific things should stay in the zsh config and then the zsh config should source the bash config.