Remove unecessary comments, improve other relevant ones

Author: josevalim

guides/directory_structure.md

@@ -49,16 +49,10 @@ The `lib/hello/application.ex` file defines an Elixir application named `Hello.A
 
 ```elixir
 children = [
-  # Start the Telemetry supervisor
   HelloWeb.Telemetry,
-  # Start the Ecto repository
   Hello.Repo,
-  # Start the PubSub system
   {Phoenix.PubSub, name: Hello.PubSub},
-  # Start the Endpoint (http/https)
   HelloWeb.Endpoint
-  # Start a worker by calling: Hello.Worker.start_link(arg)
-  # {Hello.Worker, arg}
 ]
 ```
 

guides/mix_tasks.md

@@ -599,7 +599,6 @@ We certainly should follow the instructions and add our new repo to our supervis
 ```elixir
 . . .
 children = [
-  # Start the Ecto repository
   Hello.Repo,
   # Our custom repo
   OurCustom.Repo,

installer/templates/phx_single/lib/app_name/application.ex

@@ -8,18 +8,15 @@ defmodule <%= @app_module %>.Application do
   @impl true
   def start(_type, _args) do
     children = [
-      # Start the Telemetry supervisor
       <%= @web_namespace %>.Telemetry,<%= if @ecto do %>
-      # Start the Ecto repository
       <%= @app_module %>.Repo,<% end %>
-      # Start the PubSub system
       {Phoenix.PubSub, name: <%= @app_module %>.PubSub},<%= if @mailer do %>
-      # Start Finch
+      # Start the Finch HTTP client for sending emails
       {Finch, name: <%= @app_module %>.Finch},<% end %>
-      # Start the Endpoint (http/https)
-      <%= @endpoint_module %>
       # Start a worker by calling: <%= @app_module %>.Worker.start_link(arg)
-      # {<%= @app_module %>.Worker, arg}
+      # {<%= @app_module %>.Worker, arg},
+      # Start to serve requests, typically the last entry
+      <%= @endpoint_module %>
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html

installer/templates/phx_umbrella/apps/app_name/lib/app_name/application.ex

@@ -8,11 +8,9 @@ defmodule <%= @app_module %>.Application do
   @impl true
   def start(_type, _args) do
     children = [<%= if @ecto do %>
-      # Start the Ecto repository
       <%= @app_module %>.Repo,<% end %>
-      # Start the PubSub system
       {Phoenix.PubSub, name: <%= @app_module %>.PubSub}<%= if @mailer do %>,
-      # Start Finch
+      # Start the Finch HTTP client for sending emails
       {Finch, name: <%= @app_module %>.Finch}<% end %>
       # Start a worker by calling: <%= @app_module %>.Worker.start_link(arg)
       # {<%= @app_module %>.Worker, arg}

installer/templates/phx_umbrella/apps/app_name_web/lib/app_name/application.ex

@@ -8,12 +8,11 @@ defmodule <%= @web_namespace %>.Application do
   @impl true
   def start(_type, _args) do
     children = [
-      # Start the Telemetry supervisor
       <%= @web_namespace %>.Telemetry,
-      # Start the Endpoint (http/https)
-      <%= @endpoint_module %>
       # Start a worker by calling: <%= @web_namespace %>.Worker.start_link(arg)
-      # {<%= @web_namespace %>.Worker, arg}
+      # {<%= @web_namespace %>.Worker, arg},
+      # Start to serve requests, typically the last entry
+      <%= @endpoint_module %>
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html