Revert "Removed proxy container configurations"

This reverts commit 80b8f182c1719b722def6e1cda3366d24639df69.
Made scripts and readme less project-specfic by 1. moved most project-specific config into a .local-dev-vm-env config file, 2. not using portforwarding, but instead reserving a local ip for each project, 3. made comments in scripts and readme mention less project-specific matters, 4. letting containers get their container-specific environment variables from .env-files, 5. detecting and using the project root's dir name in the web container config
Clarified project structure, explained containers, clarified features and installation instructions in readme
Fixed typos
Corrected instructions about .local-dev-vm-env handling in readme
Removed unused env var from .local-dev-vm-env.dist