ヘルプを Wiki から分離 (#424) (#430)

画面上でのテストは完了．
移行にす早さが求められるので，準備ができたらマージする．

Reviewed-on: #430
Co-authored-by: miteruzo <miteruzo@naver.com>

backend/spec/support/wiki_records.rb

@@ -0,0 +1,20 @@
+# Historical records must remain seedable after application creation is frozen.
+module WikiRecords
+  def seed_wiki_page(tag_name:, body:, created_by_user:, message: nil)
+    page = WikiPage.create!(tag_name:, body:,
+                            created_user: created_by_user, updated_user: created_by_user)
+    revision = Wiki::Commit.legacy_content!(
+        page:, body:, created_user: created_by_user, message:)
+    if tag_name.tag && tag_name.language_code == 'ja'
+      TagDescription.create!(
+          id: page.id, tag: tag_name.tag, language_code: 'ja', body: page.reload.body,
+          version_no: 1, created_by_user_id: created_by_user.id,
+          updated_by_user_id: created_by_user.id)
+      TagDescriptionVersion.create!(
+          id: revision.id, tag_id: tag_name.tag_id, language_code: 'ja',
+          version_no: 1, event_type: 'create', body: page.body,
+          created_by_user_id: created_by_user.id, created_at: revision.created_at)
+    end
+    page
+  end
+end