Add alias rustup status for rustup show

The existence of `git status` makes fingers want to try `rustup status`,
but `rustup` calls that command `rustup show`. Add an alias.

Author: joshtriplett

src/cli/rustup_mode.rs

@@ -158,7 +158,7 @@ enum RustupSubcmd {
     },
 
     /// Show the active and installed toolchains or profiles
-    #[command(after_help = show_help())]
+    #[command(after_help = show_help(), aliases = ["status"])]
     Show {
         /// Enable verbose output with rustc information for all installed toolchains
         #[arg(short, long)]