Apply suggestions from code review

Looks good, thanks @sengi

Co-authored-by: Chris B <chris.banks@digital.cabinet-office.gov.uk>

lib/govuk_app_config/govuk_puma.rb

@@ -1,46 +1,28 @@
 module GovukPuma
   def self.configure_rails(config)
-    # Specifies the `port` that Puma will listen on to receive requests; default is 3000.
-    #
     config.port ENV.fetch("PORT", 3000)
 
-    # Specifies the `environment` that Puma will run in.
-    #
     config.environment ENV.fetch("RAILS_ENV", "development")
 
     if ENV["GOVUK_APP_LOGROOT"]
       config.stdout_redirect "#{ENV['GOVUK_APP_LOGROOT']}/app.out.log" "#{ENV['GOVUK_APP_LOGROOT']}/app.err.log"
     end
 
-    # Specifies the `worker_timeout` threshold that Puma will use to wait before
-    # terminating a worker in development environments.
-    #
+    # `worker_timeout` specifies how many seconds Puma will wait before terminating a worker.
     timeout = ENV.fetch("RAILS_ENV", "development") == "development" ? 3600 : 15
     config.worker_timeout timeout
 
-    # Puma can serve each request in a thread from an internal thread pool.
-    # The `threads` method setting takes two numbers: a minimum and maximum.
-    # Any libraries that use thread pools should be configured to match
-    # the maximum value specified for Puma. Default is set to 5 threads for minimum
-    # and maximum; this matches the default thread size of Active Record.
-    #
+    # When changing the mix/max threads for Puma, also consider changing ActiveRecord to match.
     max_threads_count = ENV.fetch("RAILS_MAX_THREADS", 5)
     min_threads_count = ENV.fetch("RAILS_MIN_THREADS", max_threads_count)
     config.threads min_threads_count, max_threads_count
 
-    # Specifies the number of `workers` to boot in clustered mode.
-    # Workers are forked web server processes. If using threads and workers together
-    # the concurrency of the application would be max `threads` * `workers`.
-    # Workers do not work on JRuby or Windows (both of which do not support
-    # processes).
-    #
+    # `workers` specifies the number of worker processes that Puma will fork.
+    # The overall concurrency limit is worker count * max threads per worker.
     config.workers ENV.fetch("WEB_CONCURRENCY", 2)
 
-    # Use the `preload_app!` method when specifying a `workers` number.
-    # This directive tells Puma to first boot the application and load code
-    # before forking the application. This takes advantage of Copy On Write
-    # process behavior so workers use less memory.
-    #
+    # `preload_app!` tells Puma to load application code before forking worker processes.
+    # This reduces RAM wastage by making better use of copy-on-write.
     config.preload_app!
 
     config.before_fork do |_server|