feat: Introduce release process documentation and consolidate workflows

- Added a comprehensive `RELEASE.md` document detailing the release process for `@jsonbored/opennextjs-cli` and `@jsonbored/opennextjs-mcp`, including workflow phases and triggers.
- Removed outdated changelog update and version bump workflows, consolidating their functionality into the main release workflow.
- Enhanced the release workflow to support multiple phases, including version bumping, changelog generation, building, and publishing to npm.
- Improved permissions and structure in the release workflow for better clarity and functionality.

These changes streamline the release process, ensuring better documentation and automation for package management.

Author: JSONbored