feat: 添加 README，更新 .gitignore，移除 JE-Skin/eskin-finger-sdk

- 添加 README.md 项目文档
- 更新 .gitignore 排除 JE-Skin/、eskin-finger-sdk/ 及构建产物
- 从 git 跟踪中移除 JE-Skin 和 eskin-finger-sdk

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/main.rs

@@ -16,7 +16,8 @@ fn main() -> eframe::Result<()> {
         renderer: eframe::Renderer::Wgpu,
         viewport: egui::ViewportBuilder::default()
             .with_inner_size([1920.0, 1080.0])
-            .with_min_inner_size([1280.0, 720.0]),
+            .with_min_inner_size([1280.0, 720.0])
+            .with_decorations(false),
         ..Default::default()
     };