Add read-only mount support for home_share through "home_paths_read_only"

[Syntrait]

See: #111

Now, a snippet like this works as expected:

[home_share]
home_paths = [
    "Downloads",
    ".config/zen",
    ".cache/zen"
]
home_paths_read_only = [
    ".themes",
    ".config/gtk-3.0"
]