Add signkey create

- Add a CLI command for creating a new signing key.

src/cli/cli_args.rs

@@ -18,7 +18,7 @@ pub struct CliArgs {
     #[clap(
         long,
         global = true,
-        help = "Certification store (SEQUOIA_HOME).",
+        help = "Certificate store (SEQUOIA_HOME).",
     )]
     pub home: Option<String>,
 
@@ -207,6 +207,7 @@ pub struct SignkeyCommand {
 #[derive(Debug, Subcommand)]
 pub enum SignkeySubcommand {
     Set(SignkeySetCommand),
+    Create(SignkeyCreateCommand),
     #[clap(
         about = "Show the fingerprint of the signing key."
     )]
@@ -239,3 +240,19 @@ pub struct SignkeySetCommand {
     pub cert: Option<String>,
 }
 
+
+#[derive(Parser, Debug)]
+#[clap(
+    about = "Create a new signing key.",
+)]
+pub struct SignkeyCreateCommand {
+    #[clap(
+        long,
+        help = "Set the userid of the new key.",
+        value_name = "USERID",
+        default_value = "Husk signing key",
+    )]
+    pub userid: String,
+}
+
+