Add documentation to maven-release-process workflow on GitHub

[bryanboza]

Problem Statement

As dotCMS developer, we need to know how this action works and how to fire a new release in case that need to create a one. Also need to know what extra configuration we can set and what we can change in case of need a custom release

Steps to Reproduce

• Navigate to the dotCMS GitHub actions
• Make sure the maven-release-preocess.yml have their own documentation

Acceptance Criteria

• Need to add an .md with the doc of the workflow.

dotCMS Version

dotCMS trunk

Proposed Objective

Quality Assurance

Proposed Priority

Priority 2 - Important

[bryanboza]

Done! https://github.com/dotCMS/core/blob/master/.github/workflows/maven-release-process.md