docs: refactor document structure and add configs, metrics, node desc…

[liukuijun666]

What does this PR do

refactor document structure and add configs, metrics, node description

Rationale for this change

This pull request includes significant updates to the configuration documentation in docs/content.en/docs/references/config.md. The changes primarily focus on reorganizing and expanding the configuration sections for better clarity and completeness.

Reorganization and expansion of configuration sections:

• Added a new "Path" section to describe instance configuration, data, and log directories with examples.
• Introduced a "Log" section to detail log configuration options, including log level, debug mode, and log format, with examples.
• Created a "Configs" section to manage instance configuration, including auto-reload, configuration management, and TLS settings, with examples.
• Added a "Metrics" section to describe system metrics collection configuration, including network, memory, disk, and CPU metrics, with examples.
• Introduced a "Node" section for instance node configuration, including IP patterns, labels, and tags, with examples.

Standards checklist

• The PR title is descriptive
• The commit messages are semantic
• Necessary tests are added
• Updated the release notes
• Necessary documents have been added if this is a new feature
• Performance tests checked, no obvious performance degradation

[medcl]

instance was not mentiond in the above context, and How about:

Common configuration for paths, including data and log directories for the Gateway.