This updates the usrdir option to look in /Users/ rather than /home/ when running on macOS, as this is where users' home directories live on this OS.
It also updates the config file's description of the option to hopefully be home directory agnostic.
The "proxy_all" option from the sample configuration not being quoted was throwing this error when running the server:
Config error: invalid TOML value, did you mean to use a quoted string? at line 38 column 13
This patch makes sure the program will run against the included example config.toml.
