feat: 🎸 update README.md

README.md

@@ -1,6 +1,10 @@
-# push_puzzle
+# Sokoban Push Puzzle
 
-A new Flutter project.
+## Usage
+
+```
+flutter run
+```
 
 ## Getting Started
 
@@ -14,3 +18,24 @@ A few resources to get you started if this is your first Flutter project:
 For help getting started with Flutter development, view the
 [online documentation](https://docs.flutter.dev/), which offers tutorials,
 samples, guidance on mobile development, and a full API reference.
+
+## Contributor
+
+### copyright holder
+
+Sokoban (100+ tiles)
+
+[Kenney](https://opengameart.org/content/sokoban-100-tiles)
+
+I appreciate it very much.
+
+## Author
+
+**Daisuke Takayama**
+
+-   [@webcyou](https://twitter.com/webcyou)
+-   [@panicdragon](https://twitter.com/panicdragon)
+-   <https://github.com/webcyou>
+-   <https://github.com/webcyou-org>
+-   <https://github.com/panicdragon>
+-   <https://www.webcyou.com/>