Initial text cleanup

src/queue.jl

@@ -4,7 +4,7 @@
 # Today those are backed by an in-process, bounded, thread-safe buffer
 # (the Go-channel / Julia-`Channel` model). To move to RabbitMQ (or any broker)
 # later, implement a new `JobQueue` subtype with these three methods and swap
-# the construction in `run` — no HTTP handler or worker code needs to change.
+# the construction in `run`. No HTTP handler or worker code needs to change.
 
 abstract type JobQueue end
 
@@ -30,7 +30,7 @@ function enqueue! end
     dequeue!(q) -> Union{Job,Nothing}
 
 Blocks until a job is available and returns it. Returns `nothing` only when the
-queue has been closed *and* fully drained — the signal for a worker to exit.
+queue has been closed *and* fully drained, which is a worker's signal to exit.
 """
 function dequeue! end