Document tips for using UnityDataTool with Library AssetDatabase artifacts

The AssetDatabase uses binary serialized files to represent imported Assets.

UnityDataTool can read such files, e.g. the dump command and can be a nicer alternative to the older binary2text tool that is typically used for this case.

It should only be necessary to look in these files in quite advanced cases. But it could be useful when developing custom scripted importers, or education about how Unity works, or for tracking a problem through the full pipeline from source to build output (e.g. for FBX files, or Scenes)

The Import Activity window shows Artifacts and has a "Show in Explorer" option for retrieving that artifact as a file. This is worth describing. We should also show how to do this from script (if possible using public APIs?)

Note: There are some changes in how these artifacts represented in recent versions of Unity, e.g. introduction of Unity Data Store (UDS) so the topic may have make information conditional on the version of Unity.

This task is to offer some

UnityDataTool の dump コマンドと、Import Activity ウィンドウの "Show in Explorer" ワークフローから始めます。公開されているスクリプティング API でアーティファクトを取得できるかを確認し、Unity Data Store などのバージョン差異を考慮します。ドキュメントは、アーティファクトへのアクセス、関連するユースケース、およびこれらの注意点を説明できた時点で完成です。