license: add reference to Unity-chan license (#602)

* add links to Unity-chan license in the samples
* add links to Unity-chan license in readme
* update meta

Author: sindharta

AutoGenerateParts/ReadmeFooter.md

@@ -31,3 +31,8 @@ git config --local core.symlinks true
 git config --global core.symlinks true
 ```
 
+## License
+* Source Code: [Unity Companion License](com.unity.toonshader/LICENSE.md)
+* Unity-chan Assets: [Unity-Chan License](http://unity-chan.com/contents/guideline_en/)  
+  These assets can be located under, but not limited to, the following folder:
+    - `com.unity.toonshader/Samples~`

com.unity.toonshader/Samples~/Built-In_RP/UnityChan/UnityChanLicense.txt

@@ -0,0 +1,12 @@
+SD Unity-Chan 3D Model Data
+Unity Technologies Japan
+
+This digital asset data is released based on the "Unity-Chan License Agreement (UCL)" (the latest version at the time of distribution is UCL 3.0).
+
+Please refer to the following for the latest version of the "Unity-Chan License Agreement".
+* Guidelines: https://unity-chan.com/contents/guideline_en/
+* License Terms: https://unity-chan.com/contents/license_en/
+
+The FAQ provides detailed guidance on what creators can and cannot do under this license, with specific examples.
+Please read the FAQ before using the content or code.
+

com.unity.toonshader/Samples~/Built-In_RP/UnityChan/UnityChanLicense.txt.meta

@@ -0,0 +1,12 @@
+SD Unity-Chan 3D Model Data
+Unity Technologies Japan
+
+This digital asset data is released based on the "Unity-Chan License Agreement (UCL)" (the latest version at the time of distribution is UCL 3.0).
+
+Please refer to the following for the latest version of the "Unity-Chan License Agreement".
+* Guidelines: https://unity-chan.com/contents/guideline_en/
+* License Terms: https://unity-chan.com/contents/license_en/
+
+The FAQ provides detailed guidance on what creators can and cannot do under this license, with specific examples.
+Please read the FAQ before using the content or code.
+

com.unity.toonshader/Samples~/HDRP/UnityChan/UnityChanLicense.txt

@@ -0,0 +1,12 @@
+SD Unity-Chan 3D Model Data
+Unity Technologies Japan
+
+This digital asset data is released based on the "Unity-Chan License Agreement (UCL)" (the latest version at the time of distribution is UCL 3.0).
+
+Please refer to the following for the latest version of the "Unity-Chan License Agreement".
+* Guidelines: https://unity-chan.com/contents/guideline_en/
+* License Terms: https://unity-chan.com/contents/license_en/
+
+The FAQ provides detailed guidance on what creators can and cannot do under this license, with specific examples.
+Please read the FAQ before using the content or code.
+