Global nav: add two new pages for VS Code extension

Add navigation item to global navigation

• Link to the merge request that introduced the new page: gitlab!167361 (merged)
• Give the MR a descriptive title.
• Optional. Link to the review app showing the new page:
  • https://main-ee-167361.docs.gitlab-review.app/ee/editor_extensions/visual_studio_code/ssl.html
  • https://main-ee-167361.docs.gitlab-review.app/ee/editor_extensions/visual_studio_code/troubleshooting.html

The new pages will be:

• https://docs.gitlab.com/ee/editor_extensions/visual_studio_code/ssl.html
• https://docs.gitlab.com/ee/editor_extensions/visual_studio_code/troubleshooting.html (or something similar, because long)

Related

• Related to Move VS Code pages (SSL and troubleshooting) to... (gitlab!167361 - merged) which moves the info into the monolith
• Related to Plan for migrating VS Code user documentation (gitlab-vscode-extension#1530)
• Enables docs: VS Code: truncate troubleshooting and SSL... (gitlab-vscode-extension!2001 - merged)
• Enables docs: Update location of troubleshooting page (gitlab-org/editor-extensions/gitlab-lsp!878 - merged) link fix in the Language Server