git-sugpatch: Print usage with no suggestion argumenet

Add `Options` to `Config` to allow us to get a usage string from a
`Config` instance, which is where we create `Options`.

Needed to remove the `Debug` derive on `Config` in order to add the
field as `Options` doesn't implement `Debug`.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/bin/git-sugpatch.rs b/src/bin/git-sugpatch.rs
index 9b2769a..c8fc0a8 100644
--- a/src/bin/git-sugpatch.rs
+++ b/src/bin/git-sugpatch.rs
@@ -20,6 +20,11 @@ fn main() {
     };
 
     if config.suggestions.is_empty() {
+        print!(
+            "{}",
+            config.usage("usage: git sugpatch [options] <suggestion>..."),
+        );
+
         process::exit(exitcode::USAGE);
     }