Feature request: set config path path from environment variable

Hi 👋🏼 I have multiple workspaces for different projects and or client and I would like to have separate configuration files. When using a tool like `direnv` or `mise`, it's straightforward to set environment variables by workspace, and it would be very practical to be able to set a `$HARLEQUIN_CONFIG_PATH` for each workspace to avoid passing `--config-path xxxx` each time I run Harlequin. Is it something acceptable to you? Would you accept a pull request adding this feature? (unless you already have some plan for this and prefer to do it yourself)