[vulnerability] Fix broken link for vulnerabilty.id

[nicpenning]

The current link for vulnerability.id is: https://cve.mitre.org/about/faqs.html#what_is_cve_id) which is a broken link.

This PR makes the link useable as: https://cve.mitre.org/about/faqs.html#what_is_cve_id

[cla-checker-service]

❌ Author of the following commits did not sign a Contributor Agreement:
0da9738,

Please, read and sign the above mentioned agreement if you want to contribute to this project

[github-actions]

Documentation changes preview: https://ecs_bk_2327.docs-preview.app.elstc.co/diff

[nicpenning]

I have already signed the CLA. Can anyone see what might be happening here?

[ebeahan]

@nicpenning Most likely because the email address in the commit is different than what you've signed the CLA with: https://github.com/elastic/ecs/commit/0da9738d0c0dbfd4a2869d1477c39e26ccc57ca5.patch

[nicpenning]

Dang, that was an accident from my local computer. Anyway to override that? It came from my github repo.

[nicpenning]

Started over: #2328