Language overhaul and Workstation 3.1 scope updates

[mendix-nleimer]

AI assisted + human revied language and formatting overhaul

Additional changes
Getting started

• adding comment about custom proxy settings
• moving marketplace links under system requirements
  Installation and configuration
• improved language and clarity of quick start guide and removing out of place marketplace links (fits neither into quick start or advanced config and quick starts links to them already in the appropriate step)
• adding documentation about new features and advanced configuration of Workspaces and Stations
  Troubleshooting
• adding more troubleshooting tips for the WS Client

[mendix-nleimer]

@katarzyna-koltun-mx Could you please inspect the suggested new document structure of Installation and configuration and leave feedback? The goal is to add a more advanced configuration section to describe all the additional features that haven't been documented so far and that would blow up the scope of the quick start guide.