docs!: Docs information architecture refactor

[bpmutter]

Summary

This document contains proposed changes to the information architecture in the ESLint documentation website, https://eslint.org/docs.

On a high level, the proposed information architecture breaks the content into the following sections:

• Use ESLint in Your Project: A refactor of the current User Guide
• Extend ESLint: A refactor of the current Developer Guide, with some content moved to the section Maintain ESLint and Community Contributions
• Maintain ESLint: Expansion of current Maintainer Guide, with some content taken from the current ‘Developer Guide’.
• Community Contributions: Expansion of the current Contributing section of the Developer Guide.

Related Issues

• Documentation Update Project eslint/eslint#16365