Convert README and CONTRIBUTING from Markdown to AsciiDoc

[lemeurherve]

Follow-up of my first (misplaced) suggestions on the "Disambiguate and document the closure process" pull request: #7516 (comment)

This PR converts the existing two Markdown documents present in the root folder to Asciidoc, in order to be able to move the /docs/MAINTAINERS.adoc file in the root folder too as it's alone in this /docs/ folder. (Subsequent PR: #7528)

Testing done

Visual inspection and comparison of the rendered AsciiDoc (README.adoc and CONTRIBUTING.adoc) with the original Markdown to confirm there were no rendering errors.

Notes / compromises concerning both documents:

GitHub renders Asciidoc with a bigger line spacing than Markdown.

Concerning CONTRIBUTING:

The "exclamation" Asciidoc render at the beginning differs from the Markdown one, I didn't find a way to include this emoticon without the block. Open to alternatives.

The IntelliJ listed options are now correctly displayed in Asciidoc.

As there can be only one "level 0" section, I had to change the level of the "Links" section title at the end.

Proposed changelog entries

N/A

Proposed upgrade guidelines

N/A

Submitter checklist

• The Jira issue, if it exists, is well-described.
• The changelog entries and upgrade guidelines are appropriate for the audience affected by the change (users or developers, depending on the change) and are in the imperative mood (see examples).
  • Fill in the Proposed upgrade guidelines section only if there are breaking changes or changes that may require extra steps from users during upgrade.
• There is automated testing or an explanation as to why this change has no tests.
• New public classes, fields, and methods are annotated with @Restricted or have @since TODO Javadocs, as appropriate.
• New deprecations are annotated with @Deprecated(since = "TODO") or @Deprecated(forRemoval = true, since = "TODO"), if applicable.
• New or substantially changed JavaScript is not defined inline and does not call eval to ease future introduction of Content Security Policy (CSP) directives (see documentation).
• For dependency updates, there are links to external changelogs and, if possible, full differentials.
• For new APIs and extension points, there is a link to at least one consumer.

Desired reviewers

@basil

Maintainer checklist

Before the changes are marked as ready-for-merge:

• There are at least two (2) approvals for the pull request and no outstanding requests for change.
• Conversations in the pull request are over, or it is explicit that a reviewer is not blocking the change.
• Changelog entries in the pull request title and/or Proposed changelog entries are accurate, human-readable, and in the imperative mood.
• Proper changelog labels are set so that the changelog can be generated automatically.
• If the change needs additional upgrade steps from users, the upgrade-guide-needed label is set and there is a Proposed upgrade guidelines section in the pull request title (see example).
• If it would make sense to backport the change to LTS, a Jira issue must exist, be a Bug or Improvement, and be labeled as lts-candidate to be considered (see query).

[lemeurherve]

I'm a bit disappointed GitHub didn't keep the "moved" state for the two files like in my first commit ae713a3 specifically isolated for an easier review.

[basil]

Very nice! The Jenkins project loves AsciiDoc, so this not only improves consistency within this repository but also consistency with the broader Jenkins ecosystem, such as jenkins-infra/jenkins.io (which heavily relies on AsciiDoc).

[MarkEWaite]

Looks great to me. One optional comment that the link to friendly issues would probably be better if it opened the friendly issues table rather than the list of friendly issues. That is optional. Thanks!

[MarkEWaite]

This PR is now ready for merge. We will merge it after approximately 24 hours if there is no negative feedback.

[NotMyFault]

Merging as-is has broken all of our, and third party, links to contributing.md, see Building and Debugging Jenkins on jenkins.io for just one example.

[oleg-nenashev]

Note that it will also break all external links to CONTRIBUTING, and we heavily use them e.g. in GSoC materials

…

On Sat, Dec 17, 2022 at 9:58 PM Alexander Brandes ***@***.***> wrote: Merging as-is has broken all of our, and third party, links to contributing.md, see Building and Debugging Jenkins on jenkins.io <https://www.jenkins.io/doc/developer/building/#references> for just one example. — Reply to this email directly, view it on GitHub <#7527 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAW4RIBXEW2NZFUD5ZWMO5LWNYSO7ANCNFSM6AAAAAATAII43I> . You are receiving this because your review was requested.Message ID: ***@***.***>

[NotMyFault]

Created #7533 to revert this for now.

[lemeurherve]

I should have though about that, sorry and thanks Alex for taking care of the revert.

I'll rework it next week, maybe something like a redirection for example.
WDYT?

[NotMyFault]

I'll rework it next week, maybe something like a redirection for example.

Sounds good, I'm open to alternative approaches, that don't break existing URLs for sure. To be fair, I was under the impression GH warrants redirections, maybe that applies to GH pages only 🤷🏻