chore: fix some trivial typos (#1225)

Fixes typos in Rustdoc and makes explicit use of `dyn`.

tracing-subscriber/src/fmt/mod.rs

@@ -338,7 +338,7 @@ pub struct CollectorBuilder<
 
 /// Returns a new [`CollectorBuilder`] for configuring a [formatting collector].
 ///
-/// This is essentially shorthand for [`CollectorBuilder::default()]`.
+/// This is essentially shorthand for [`CollectorBuilder::default()`].
 ///
 /// # Examples
 ///

tracing-subscriber/src/registry/extensions.rs

@@ -133,7 +133,7 @@ impl ExtensionsInner {
             .and_then(|boxed| {
                 #[allow(warnings)]
                 {
-                    (boxed as Box<Any + 'static>)
+                    (boxed as Box<dyn Any + 'static>)
                         .downcast()
                         .ok()
                         .map(|boxed| *boxed)
@@ -162,7 +162,7 @@ impl ExtensionsInner {
         self.map.remove(&TypeId::of::<T>()).and_then(|boxed| {
             #[allow(warnings)]
             {
-                (boxed as Box<Any + 'static>)
+                (boxed as Box<dyn Any + 'static>)
                     .downcast()
                     .ok()
                     .map(|boxed| *boxed)

tracing-subscriber/src/subscribe.rs

@@ -68,7 +68,7 @@ use std::{any::TypeId, marker::PhantomData};
 /// }
 ///
 /// # use tracing_core::{span::{Id, Attributes, Record}, Metadata, Event};
-/// impl Collect for MySubscriber {
+/// impl Collect for MyCollector {
 ///     // ...
 /// #   fn new_span(&self, _: &Attributes) -> Id { Id::from_u64(1) }
 /// #   fn record(&self, _: &Id, _: &Record) {}
@@ -85,7 +85,7 @@ use std::{any::TypeId, marker::PhantomData};
 /// # fn new() -> Self { Self { }}
 /// # }
 ///
-/// let collector = MySubscriber::new()
+/// let collector = MyCollector::new()
 ///     .with(MySubscriber::new());
 ///
 /// tracing::collect::set_global_default(collector);