Update upstream info

Author: williamd1k0

README.md

@@ -4,11 +4,12 @@
 
 A pixel art icon pack based on [MBE Style](https://github.com/iAcn/MBEStyle) project by [@iAcn](https://github.com/iAcn/).
 
-Developer: Leon连续 @Coolapk
+Pixel Art Designer: [@williamd1k0](https://github.com/williamd1k0/)
 
-HD Designer: 幼幼保护协会 @Coolapk
+> Upstream:
+> - Developer: Leon连续 @Coolapk
+> - HD Designer: 幼幼保护协会 @Coolapk
 
-Pixel Art Designer: [@williamd1k0](https://github.com/williamd1k0/)
 
 Icon guidelines: [Creating a Pixelart Icon Pack - Tumeo Space](https://tumeo.space/blogs/2019/03/11/pixelart-icons/)