docs(cookbook): Style cargo plugin

Inspired by part of the conversation at #3234

Author: epage

Cargo.lock

@@ -187,18 +187,19 @@ humantime = "2.1.0"
 snapbox = "0.6.16"
 shlex = "1.3.0"
 automod = "1.0.14"
+clap-cargo = { version = "0.14.1", default-features = false }
 
 [[example]]
 name = "demo"
 required-features = ["derive"]
 
 [[example]]
 name = "cargo-example"
-required-features = ["cargo"]
+required-features = ["cargo", "color"]
 
 [[example]]
 name = "cargo-example-derive"
-required-features = ["derive"]
+required-features = ["derive", "color"]
 
 [[example]]
 name = "escaped-positional"

Cargo.toml

@@ -3,10 +3,21 @@ use clap::Parser;
 #[derive(Parser)] // requires `derive` feature
 #[command(name = "cargo")]
 #[command(bin_name = "cargo")]
+#[command(styles = CLAP_STYLING)]
 enum CargoCli {
     ExampleDerive(ExampleDeriveArgs),
 }
 
+// See also `clap_cargo::style::CLAP_STYLING`
+pub const CLAP_STYLING: clap::builder::styling::Styles = clap::builder::styling::Styles::styled()
+    .header(clap_cargo::style::HEADER)
+    .usage(clap_cargo::style::USAGE)
+    .literal(clap_cargo::style::LITERAL)
+    .placeholder(clap_cargo::style::PLACEHOLDER)
+    .error(clap_cargo::style::ERROR)
+    .valid(clap_cargo::style::VALID)
+    .invalid(clap_cargo::style::INVALID);
+
 #[derive(clap::Args)]
 #[command(version, about, long_about = None)]
 struct ExampleDeriveArgs {

examples/cargo-example-derive.rs

@@ -1,6 +1,7 @@
 fn main() {
     let cmd = clap::Command::new("cargo")
         .bin_name("cargo")
+        .styles(CLAP_STYLING)
         .subcommand_required(true)
         .subcommand(
             clap::command!("example").arg(
@@ -16,3 +17,13 @@ fn main() {
     let manifest_path = matches.get_one::<std::path::PathBuf>("manifest-path");
     println!("{manifest_path:?}");
 }
+
+// See also `clap_cargo::style::CLAP_STYLING`
+pub const CLAP_STYLING: clap::builder::styling::Styles = clap::builder::styling::Styles::styled()
+    .header(clap_cargo::style::HEADER)
+    .usage(clap_cargo::style::USAGE)
+    .literal(clap_cargo::style::LITERAL)
+    .placeholder(clap_cargo::style::PLACEHOLDER)
+    .error(clap_cargo::style::ERROR)
+    .valid(clap_cargo::style::VALID)
+    .invalid(clap_cargo::style::INVALID);

examples/cargo-example.rs

@@ -15,6 +15,7 @@
 //! - Topics:
 //!   - Subcommands
 //!   - Cargo plugins
+//!   - custom terminal [styles][crate::Command::styles] (colors)
 //!
 //! find-like interface: [builder][find]
 //! - Topics: