Update Rust example in cli.md (#2337)

* Update cli.md

Updating the example Rust code with an example graciously provided by @amrbashir . This is also in response to a [docs issue](https://github.com/tauri-apps/tauri/issues/2332) that I had raised earlier.

* Update docs/usage/guides/cli.md

* Update cli.md

* Update cli.md

Co-authored-by: Amr Bashir <48618675+amrbashir@users.noreply.github.com>

docs/usage/guides/cli.md

@@ -123,16 +123,25 @@ Its configuration is the same as the root application configuration, with the `d
 ### Rust
 
 ```rust
-use tauri::cli::get_matches;
+use tauri::api::cli::get_matches;
 
 fn main() {
-  match get_matches() {
-    Some(matches) => {
-      // `matches` here is a Struct with { args, subcommand }
-      // where args is the HashMap mapping each arg's name to it's { value, occurrences }
-      // and subcommand is an Option of { name, matches }
+  let context = tauri::generate_context!();
+  let cli_config = context.config().tauri.cli.clone().unwrap();
+  
+  match get_matches(&cli_config) {
+    // `matches` here is a Struct with { args, subcommand }.
+    // `args` is `HashMap<String, ArgData>` where `ArgData` is a struct with { value, occurances }.
+    // `subcommand` is `Option<Box<SubcommandMatches>>` where `SubcommandMatches` is a struct with { name, matches }.
+    Ok(matches) => {
+      println!("{:?}", matches)
     }
-  }
+    Err(_) => {}
+  };
+  
+  tauri::Builder::default()
+  .run(context)
+  .expect("error while running tauri application");
 }
 ```