Add license scan report and status (#522)

Your FOSSA integration was successful! Attached in this PR is a badge
and license report to track scan status in your README.

Below are docs for integrating FOSSA license checks into your CI:

- [CircleCI](https://docs.fossa.com/docs/circleci)
- [TravisCI](https://docs.fossa.com/docs/travisci)
- [Jenkins](https://github.com/fossas/fossa-jenkins-plugin)
- [Other](https://github.com/fossas/fossa-cli)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit

- **ドキュメント**
	- ライセンス情報のためのFOSSAステータスバッジを追加しました。

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Taku Fukada <[email protected]>

README.md

@@ -3,6 +3,7 @@
 [![Test Tauri App](https://github.com/MIERUNE/plateau-gis-converter/actions/workflows/test_app.yml/badge.svg)](https://github.com/MIERUNE/nusamai/actions/workflows/test_app.yml)
 [![Test Libraries](https://github.com/MIERUNE/plateau-gis-converter/actions/workflows/test_libs.yml/badge.svg)](https://github.com/MIERUNE/nusamai/actions/workflows/test_libs.yml)
 [![Codecov](https://codecov.io/gh/MIERUNE/plateau-gis-converter/graph/badge.svg?token=oa62wDWoqu)](https://codecov.io/gh/MIERUNE/plateau-gis-converter)
+[![FOSSA Status](https://app.fossa.com/api/projects/git%2Bgithub.com%2FMIERUNE%2Fplateau-gis-converter.svg?type=shield)](https://app.fossa.com/projects/git%2Bgithub.com%2FMIERUNE%2Fplateau-gis-converter?ref=badge_shield)
 
 <!--
 [![Docs](https://github.com/MIERUNE/plateau-gis-converter/actions/workflows/doc.yml/badge.svg)](https://mierune.github.io/nusamai/app/)