docs: wrap shorthand admonition blocks in ==== delimiters

[rolfedh]

Summary

Across 13 guides in docs/src/main/asciidoc/, single-paragraph admonitions use the bare-attribute shorthand ([NOTE] / [TIP] / [WARNING] on a line by itself, followed by a single paragraph, no ==== delimiters). The shorthand form renders in Asciidoctor but:

• produces inconsistent output across renderers (Asciidoctor vs. DITA vs. downstream tooling),
• hinders programmatic content transformation (linters and doc pipelines have to special-case both forms).

Wrap each affected block in the explicit ==== delimited form. No content changes — 38 lines added, 0 removed, all of them ==== delimiter lines.

Files touched (19 blocks across 13 files)

• aws-lambda-http.adoc
• building-my-first-extension.adoc
• building-native-image.adoc
• getting-started-dev-services.adoc
• getting-started-testing.adoc
• gradle-tooling.adoc (4 blocks)
• hibernate-search-orm-elasticsearch.adoc (2 blocks)
• hibernate-search-standalone-elasticsearch.adoc (2 blocks)
• mailer-reference.adoc (2 blocks)
• quarkus-reactive-architecture.adoc
• redis-reference.adoc
• rest-client.adoc
• security-customization.adoc

[quarkus-bot]

Thanks for your pull request!

Your pull request does not follow our editorial rules. Could you have a look?

• title should preferably start with an uppercase character (if it makes sense!)
• title should not start with chore/docs/feat/fix/refactor but be a proper sentence

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[quarkus-bot]

Status for workflow Quarkus Documentation CI

This is the status report for running Quarkus Documentation CI on commit dc6be24.

Failing Jobs

Status	Name	Step	Failures	Logs	Raw logs	Build scan
❌	Documentation Build	Build	Failures	Logs	Raw logs	🚧

Failures

⚙️ Documentation Build #

- Failing: docs 

📦 docs

❌ Failed to execute goal org.asciidoctor:asciidoctor-maven-plugin:3.2.0:process-asciidoc (output-html) on project quarkus-documentation: Found 2 issue(s) of severity WARN or higher during conversion