rust: Add support for doctest runnables (#24806)

Screenshot:


![image](https://github.com/user-attachments/assets/0ac88029-76c1-4135-bef2-373636e3587d)

I would be happy to add tests if you point me to the right place to do
it please.

Release Notes:

- Added support for doc test in tasks for Rust

---------

Signed-off-by: Benjamin <5719034+bnjjj@users.noreply.github.com>

crates/languages/src/rust.rs

@@ -577,6 +577,26 @@ impl ContextProvider for RustContextProvider {
                 cwd: Some("$ZED_DIRNAME".to_owned()),
                 ..TaskTemplate::default()
             },
+            TaskTemplate {
+                label: format!(
+                    "DocTest '{}' (package: {})",
+                    VariableName::Symbol.template_value(),
+                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
+                ),
+                command: "cargo".into(),
+                args: vec![
+                    "test".into(),
+                    "--doc".into(),
+                    "-p".into(),
+                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
+                    VariableName::Symbol.template_value(),
+                    "--".into(),
+                    "--nocapture".into(),
+                ],
+                tags: vec!["rust-doc-test".to_owned()],
+                cwd: Some("$ZED_DIRNAME".to_owned()),
+                ..TaskTemplate::default()
+            },
             TaskTemplate {
                 label: format!(
                     "Test '{}' (package: {})",