AO3-6553 Bonus i18n for media on homepage

This is not strictly related to the a11y issue, but we're trying to add
i18n if we can when we touch a file.

app/models/media.rb

@@ -8,6 +8,10 @@ def child_types
     ['Fandom']
   end
 
+  def translation_key
+    name.parameterize(separator: "_")
+  end
+
   # The media tag for unwrangled fandoms
   def self.uncategorized
     tag = self.find_or_create_by_name(ArchiveConfig.MEDIA_UNCATEGORIZED_NAME)

app/views/menu/_menu_fandoms.html.erb

@@ -4,7 +4,7 @@
     <% cache "menu-fandoms-version4", skip_digest: true do %>
       <% Media.for_menu.each do |medium| %>
         <% unless medium.id.nil? %>
-          <li id="medium_<%= medium.id %>"><%= link_to ts("#{medium.name}", key: 'header.fandom'), medium_fandoms_path(medium) %></li>
+          <li id="medium_<%= medium.id %>"><%= link_to t(".#{medium.translation_key}"), medium_fandoms_path(medium) %></li>
         <% end %>
       <% end %>
     <% end %>

config/locales/views/en.yml

@@ -453,7 +453,17 @@ en:
   menu:
     menu_fandoms:
       all_fandoms: All Fandoms
+      anime_manga: Anime & Manga
+      books_literature: Books & Literature
+      cartoons_comics: Cartoons & Comics
       media: Media
+      movies: Movies
+      music_bands: Music & Bands
+      other_media: Other Media
+      real_people_celebrities: Real People & Celebrities
+      tv_shows: TV Shows
+      uncategorized_fandoms: Uncategorized Fandoms
+      video_games: Video Games
   muted:
     mute: Mute
     muted_items_notice_html: You have muted some users on the Archive. Some items may not be shown, and any counts may be inaccurate. You can mute or unmute users on %{muted_users_link}.

spec/models/media_spec.rb

@@ -0,0 +1,10 @@
+require 'spec_helper'
+
+describe Media do
+  describe "#translation_key" do
+    it "returns a parameterized version of the media name using underscore as a separator" do
+      media = FactoryBot.create(:media, name: "Widgets; Tools & Doodads")
+      expect(media.translation_key).to eql("widgets_tools_doodads")
+    end
+  end
+end