feat(docs): add @Sample annotation for documentation

[Choconaut]

Marks integration test classes so that markdown pages can be auto generated.

[Choconaut]

I wasn't sure where to place @sample, so I put it in a temporary module for now. I thought about putting it in sample-operators. Do you have any recommendations? I'm happy to move it.

[csviri]

I think that is fine by now, since the implementation will be I guess an annotation processor.

[metacosm]

I'm not sure these properties are needed here since they should probably be inherited from the parent. Also, this code should work with Java 21.

[Copilot]

Pull Request Overview

This PR introduces a @Sample annotation and corresponding annotation processor to enable automatic generation of markdown documentation from integration test classes. The feature allows developers to mark test classes with metadata that gets compiled into a samples.md file for documentation purposes.

• Adds a new @Sample annotation with tldr and description fields for marking integration test classes
• Implements a SampleProcessor annotation processor that collects annotated classes and generates markdown output
• Creates a new Maven module operator-annotations to house the annotation infrastructure

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
pom.xml	Adds the new operator-annotations module to the parent POM
operator-annotations/pom.xml	Defines the new Maven module for annotation processing
operator-annotations/src/main/java/io/javaoperatorsdk/annotation/Sample.java	Defines the @sample annotation with tldr and description fields
operator-annotations/src/main/java/io/javaoperatorsdk/processor/SampleProcessor.java	Implements the annotation processor that generates samples.md from annotated classes

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[Copilot]

Empty Javadoc comment should either be removed or contain meaningful documentation describing the method's purpose, parameters, and behavior.

Suggested change

	/**
	*
	/**
	* Writes a markdown file named {@code samples.md} listing all provided samples.
	* Each sample is written as a section with its TLDR and description.
	*
	* @param samples the list of samples to include in the markdown file
	* @throws RuntimeException if an I/O error occurs during file writing