added better deployment docs

[Ajay9704]

I've updated the deployment documentation to address issue #15325. The docs were lacking information on container-based deployments, particularly around layered builds that help optimize Docker images.

I've added comprehensive coverage of:

• Traditional WAR deployments with best practices
• Container deployments using layered builds to minimize space requirements
• Standalone deployment options with optimization tips
• A new section specifically for layered builds with practical examples

The changes enhance both the existing deployment documentation and add a new section dedicated to layered builds for container deployments. This should give users better guidance on deploying Grails applications using modern containerization techniques that optimize storage and build times

[Ajay9704]

@jdaugherty can you trigger the workflows so i can see the build status