Include a doc in multiple menus

If you have a document that should appear in multiple menus, you can use a combination of a redirect and a new navigation entry.

For example, if you wanted to link to the APM landing page from a unique link from another part of the navigation tree, you’d do two things:

1. Update the docs/apm/index.mdx front matter with the URL you want to link from:

redirects:
  - /docs/unique-link

2. Add an entry in the navigation YAML file (for example, /src/nav/agents.yml):

title: APM Page with unique link
path: /docs/unique-link