Specification extensions link is broken in Markdown file

[SensibleWood]

The Specification Extensions link is broken through the specification file:

• This is the broken link
• This is the correct link

It would nice for readability of the specification if this worked.

[fariadev22]

For me as well, all links in the Table of Contents in this document are broken since a few weeks. They used to work before:

https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.3.md

[SethAngell]

Hey! I noticed the same thing and performed a slight refactor to resolve the issue! Waiting on reviews currently. See #3128

[kexoth]

Noticed this issue as well & refactored the links, see #3160
As well noticed now that mine is duplicate work with @SethAngell's PR.

[handrews]

Consolidating all broken link issues into issue #3054 and PR #3408