Sphinx-external-toc-strict

What's Changed

- ⬆️ UPGRADE: allow click v8 by lukasbindreiter in https://github.com/executablebooks/sphinx-external-toc/pull/69
- 📚: Fix ToC graphic link by ZviBaratz in https://github.com/executablebooks/sphinx-external-toc/pull/63
- 🔧 MAINTAIN: Updated parser docstrings by ZviBaratz in https://github.com/executablebooks/sphinx-external-toc/pull/61
- 🔧 MAINTAIN: Removed unused argument by ZviBaratz in https://github.com/executablebooks/sphinx-external-toc/pull/66
- 🔧 MAINTAIN: Updated `api` docstrings by ZviBaratz in https://github.com/executablebooks/sphinx-external-toc/pull/64
- 🔧: Docstring updates by ZviBaratz in https://github.com/executablebooks/sphinx-external-toc/pull/67

New Contributors

- ZviBaratz made their first contribution in https://github.com/executablebooks/sphinx-external-toc/pull/61
- lukasbindreiter made their first contribution in https://github.com/executablebooks/sphinx-external-toc/pull/69

**Full Changelog**: https://github.com/executablebooks/sphinx-external-toc/compare/v0.2.3...v0.2.4

🔧 MAINTAIN: Update `attrs` minimum version to `20.3`, when `value_serializer` was introduced (required here).

👌 IMPROVE: Changed document identification.
The comparison of sitemaps and identification of changed documents to rebuild was improved and moved to `SiteMap.get_changed`.

🐛 FIX: File extensions in ToC

Ensure files are still matched, if they are provided with file extensions.

- ⬆️ UPDATE: Relax dependency pinning to allow Sphinx v4

- ‼ BREAKING: the CLI command `to-site` is now `to-project`, and `from-site` is now `from-project`

- ♻️ REFACTOR: key `items` -> `entries`
- 👌 IMPROVE: Add `--output` to `migrate` command