docs: Tweak comments on Mailbox (#3152)

internal_types/src/mailbox.rs

@@ -10,16 +10,15 @@ use std::sync::Arc;
 /// * Allows data to continue to arrive whilst data is being consumed
 /// * Allows multiple consumers to coordinate preventing concurrent consumption
 ///
-/// This is different than a tokio channel in the following ways:
+/// This is different from a tokio channel in the following ways:
 ///
-/// 1. The contents can be inspected prior to remval from the mailbox
+/// 1. The contents can be inspected prior to removal from the mailbox
 /// (important as catalog transactions are fallible)
 ///
 /// 2. Potentially multiple consumers can acquire exclusive access for
 /// the duration of a catalog transaction
 ///
-/// 3. Users can ensure that everything in the mailbox is
-/// consumed
+/// 3. Users can ensure that everything in the mailbox is consumed
 ///
 #[derive(Debug)]
 pub struct Mailbox<T> {