Better docs

Use https://github.com/ember-learn/ember-cli-addon-docs for docs

Review the referenced ember-cli-addon-docs project and compare its expected documentation setup with this addon's current repository. The issue does not name any files, tests, or specific documentation gaps; completion would need to be defined as adopting that documentation approach and confirming the resulting docs cover the addon.

由索引模型根据 Issue 内容生成。