feat(DesignTokens): Add design token table to documentation

What does this MR do?

Embeds the design token table from gitlab-org/gitlab-ui!4190 (merged) into a standalone page in design.gitlab.com for a design token reference/search tool.

Screenshots or screen recordings

Local validation

To review changes locally, update the base URL for storybook embeds to the review app URL from gitlab-org/gitlab-ui!4190 (merged):

diff --git a/nuxt.config.js b/nuxt.config.js
index 562cf131..5e79fd62 100644
--- a/nuxt.config.js
+++ b/nuxt.config.js
@@ -14,7 +14,7 @@ const GITLAB_ANALYTICS_URL = GITLAB_ANALYTICS_ID
 const CI_ENVIRONMENT_URL = process.env.CI_ENVIRONMENT_URL || false;
 
 const GITLAB_UI_URL = (
-  process.env.GITLAB_UI_URL || 'https://gitlab-org.gitlab.io/gitlab-ui'
+  process.env.GITLAB_UI_URL || 'https://gitlab-org.gitlab.io/gitlab-ui/review-mr-4190-e8p6pk/'
 ).replace(/\/+$/, '');
 
 const LOOKBOOK_URL = (