chore: Add README and licenses to streaming assets

Assets/StreamingAssets/Messages/LICENSE.txt

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+# License
+The following files are licensed under [CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/) © Cryville and translation contributors.
+
+- Cryville.EEW.Core/*
+- Cryville.EEW.CWA/*
+- Cryville.EEW.CWAOpenData/*
+- Cryville.EEW.CWAOpenData.TTS/*
+- Cryville.EEW.FERegion/yue.json
+- Cryville.EEW.FERegion/zh.json
+- Cryville.EEW.FERegion/zh-Hant.json
+- Cryville.EEW.GlobalQuake/*
+- Cryville.EEW.JMA/*
+- Cryville.EEW.JMA/PointTsunami/en.json
+- Cryville.EEW.JMA/PointTsunami/yue.json
+- Cryville.EEW.JMA/PointTsunami/zh.json
+- Cryville.EEW.JMA/PointTsunami/zh-Hant.json
+- Cryville.EEW.JMAAtom/*
+- Cryville.EEW.JMAAtom.TTS/*
+- Cryville.EEW.NOAA/*
+- Cryville.EEW.NOAA.TTS/*
+- Cryville.EEW.UpdateChecker/*
+- Cryville.EEW.Wolfx/*
+- Cryville.EEW.Wolfx.TTS/**/*
+
+The following files are copyrighted by [Japan Meteorological Agency](https://www.jma.go.jp/jma/index.html):
+
+- Cryville.EEW.FERegion/ja.json (modified)
+- Cryville.EEW.JMA/AreaEpicenter/* (modified)
+- Cryville.EEW.JMA/AreaForecastEEW/* (modified)
+- Cryville.EEW.JMA/AreaTsunami/* (modified)
+- Cryville.EEW.JMA/PointTsunami/und.json
+- Cryville.EEW.JMA/PointVolcano/* (modified)
+
+The following files are from [Wikipedia](https://en.wikipedia.org/wiki/Flinn-Engdahl_regionalization#/map/0), licensed under [CC-BY-SA-4.0](https://creativecommons.org/licenses/by-sa/4.0/deed.en):
+
+- Cryville.EEW.FERegion/und.json (modified)

Assets/StreamingAssets/Messages/LICENSE.txt.meta

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+guid: b40f6faea5e03b341ac43a4c5e3cda0c
+DefaultImporter:
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Assets/StreamingAssets/README.txt

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+Warning: Modifying the files in this directory is NOT SUPPORTED

Assets/StreamingAssets/README.txt.meta

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+fileFormatVersion: 2
+guid: 3dba70030f98adf42bfc460e3b812a53
+DefaultImporter:
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Assets/StreamingAssets/Sounds/LICENSE.txt

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+# License
+The following files are licensed under [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0/) © kotoho7
+
+- jp/
+  - eew0.ogg
+  - eew3.ogg
+  - eew5.ogg
+  - eewC.ogg
+  - koushin.ogg
+  - koushinE.ogg
+
+The following files are licensed under [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0/) © kotoho7, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) © OtoLogic
+
+- jp/
+  - VTSE5.ogg
+  - VXSE5C.ogg
+  - VXSE51.ogg
+  - VXSE52.ogg
+  - VXSE53.ogg
+  
+The following files are licensed under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) © OtoLogic
+
+- jp/
+  - Emergency_Alert01-1-C.ogg
+  - News-Alert02-2-C.ogg
+  - News-Alert04-1-C.ogg
+
+All other files in this directory are licensed under [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/) © Cryville

Assets/StreamingAssets/Sounds/LICENSE.txt.meta

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+fileFormatVersion: 2
+guid: cce14345d934e7043b46f8c1f4174941
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: