Remove spec links to source code

[Azquelt]

In many places, the spec links directly to java files or markdown files stored in github source control.

This is not good for several reasons:

• Most of the links are to the main or master branch so the version of the linked document may no longer match the version of the spec.
• Source code can be moved or refactored at any time, breaking the links.

There are several types of links in the spec and Javadoc:

• links to the OpenAPI spec markdown
  • being updated in update version number in spec and references to spec #607 to point to the hosted HTML version of the spec at https://spec.openapis.org/oas/v3.1.0.html
• links to the MP Config spec
  • being updatd in update version number in spec and references to spec #607 to point to the hosted HTML version of the spec at https://download.eclipse.org/microprofile/microprofile-config-3.1/microprofile-config-spec-3.1.html
• links to java files from MP OpenAPI
  • ideally this would link to the Javadoc for the relevant class
    • possible, but relies on knowing ahead of time where the Javadoc is going to be for releases
    • not sure what the correct link would be when not building a release
  • it might also be acceptable to link to the source code in github using the commit hash used for the build
  • we could also consider removing the links
    • most specs discuss classes in their API without linking to them

[Azquelt]

Spotted a link to the rest client source: org.eclipse.microprofile.rest.client.inject.RegisterRestClient.