Add artifacts-bundler community tool for air-gapped endpoint setups

[pkward]

Summary

This PR adds a community-contributed example to the "Configure offline endpoints and air-gapped environments" documentation. It introduces the artifacts-bundler Bash-based CLI tool that automates downloading Elastic Stack artifacts, endpoint security content, and optionally builds an NGINX image for serving the content in air-gapped environments.

Why This Is Useful

Preparing air-gapped Elastic deployments—especially Elastic Defend with endpoint artifact requirements—is time-consuming and error-prone when done manually. This tool simplifies:

• Multi-version artifact downloading
• Endpoint manifest and global artifact fetch
• Bundle creation (.tar.gz)
• Optional Docker/Nginx server generation

This is especially helpful for DoD or offline regulated environments.

Placement

This contribution adds a dropdown section under:

Step 3: Manually copy artifact updates

in the configure-offline-endpoints-air-gapped-environments.md document. It provides an alternative method using a community-contributed Bash script to automate downloading and bundling endpoint artifacts.

[github-actions]

🔍 Preview links for changed docs

• solutions/security/configure-elastic-defend/configure-offline-endpoints-air-gapped-environments.md