* chore: 著作権とライセンスについての情報を各ファイルに追加する
* chore: Add the SPDX information to each file
Add copyright and licensing information as defined in version 3.0 of
the REUSE Specification.
* tweak format
---------
Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>
* chore: Add SPDX-License-Identifier [skip ci]
* add missing SPDX-License-Identifier
* remove unused file
---------
Co-authored-by: Shun Sakai <sorairolake@protonmail.ch>
Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>
Co-authored-by: Chocolate Pie <106949016+chocolate-pie@users.noreply.github.com>
