fix: avoid "stg.exe" in usage on Windows

The clap-generated usage lines in help output use the command's "bin name".
On Windows, the bin name has a ".exe" extension. All of StGit's man pages
and custom usage lines use "stg" without any extension. Insofar as .exe
extensions can be elided on Windows when running executables, plain "stg"
is valid on all platforms. So we set the bin name to "stg" to maintain
consistency in usage statements across StGit subcommands and across target
platforms.

Author: jpgrayson

src/main.rs

@@ -50,7 +50,7 @@ const CONFLICT_ERROR: i32 = 3;
 /// [`clap::Command`] graph as needed to execute the target subcommand; avoiding the
 /// cost of instantiating [`clap::Command`] instances for every StGit subcommand.
 fn get_base_command(color_choice: Option<termcolor::ColorChoice>) -> clap::Command {
-    let command = clap::Command::new("stg")
+    let mut command = clap::Command::new("stg")
         .about("Maintain a stack of patches on top of a Git branch.")
         .override_usage(cmd::make_usage(
             "stg",
@@ -90,6 +90,10 @@ fn get_base_command(color_choice: Option<termcolor::ColorChoice>) -> clap::Comma
                 .value_hint(clap::ValueHint::AnyPath),
         )
         .arg(color::get_color_arg().global(true).display_order(998));
+
+    // Ensure "stg" and not "stg.exe" shows up in usage on Windows.
+    command.set_bin_name("stg");
+
     if let Some(color_choice) = color_choice {
         command.color(color::termcolor_choice_to_clap(color_choice))
     } else {