Enable frozen string literals.

Make all string literals immutable by default.

app/logical/discord_slash_command/count_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class CountCommand < DiscordSlashCommand
     self.name = "count"

app/logical/discord_slash_command/post_embed.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class PostEmbed
     attr_reader :post, :command

app/logical/discord_slash_command/posts_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class PostsCommand < DiscordSlashCommand
     extend Memoist

app/logical/discord_slash_command/random_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class RandomCommand < DiscordSlashCommand
     self.name = "random"

app/logical/discord_slash_command/tagme_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class TagmeCommand < DiscordSlashCommand
     self.name = "tagme"

app/logical/discord_slash_command/time_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class TimeCommand < DiscordSlashCommand
     self.name = "time"

app/logical/discord_slash_command/wiki_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class WikiCommand < DiscordSlashCommand
     extend Memoist