Clap: Hide deprecated -o/--os argument from help

docs/src/usage.txt

@@ -15,7 +15,6 @@ OPTIONS:
     -f, --render <FILE>          Render a specific markdown file
     -p, --platform <PLATFORM>    Override the operating system [possible values: linux, macos,
                                  windows, sunos, osx]
-    -o, --os <OS>                Deprecated alias of `platform`
     -L, --language <LANGUAGE>    Override the language
     -u, --update                 Update the local cache
     -c, --clear-cache            Clear the local cache

src/main.rs

@@ -92,7 +92,7 @@ struct Args {
         short = 'o',
         long = "os",
         possible_values = ["linux", "macos", "windows", "sunos", "osx"],
-        hide_possible_values = true,
+        hide = true
     )]
     os: Option<PlatformType>,