A few documentation updates

src/kernel/thread_manager.rs

@@ -6,17 +6,26 @@ use super::{scheduler::Scheduler, thread::Thread, system::System, mgerror::Error
 
 pub const SIMULATORSTACKSIZE: usize = 32 * 1024;
 
+/// # Thread manager
+/// 
+/// An instance of this struct is responsible for managing threads on behalf of the system
 #[derive(PartialEq)]
 pub struct ThreadManager {
+    /// Current running thread
     pub g_current_thread: Option<Rc<RefCell<Thread>>>,
+    /// The thread to be destroyed next
     pub g_thread_to_be_destroyed: Option<Rc<RefCell<Thread>>>,
+    /// The list of alive threads
     pub g_alive: List<Rc<RefCell<Thread>>>,
+    /// The thread scheduler
     pub g_scheduler: Scheduler,
+    /// The system owning the thread manager
     pub system: Option<Rc<RefCell<System>>>
 }
 
 impl ThreadManager {
 
+    /// Thread manager constructor
     pub fn new() -> Self {
         Self { 
             g_current_thread: Option::None,