docs: 更新 README 和安装文档，新增 yt-studio-groupid-lookup 技能说明

scripts/install-skills.bat

@@ -1,12 +1,15 @@
 @echo off
 rem Trae CN skill installer launcher - double click to run
 rem Actual logic lives in install-skills.ps1 (same folder)
+rem Usage:  install-skills.bat                 (install ALL skills)
+rem         install-skills.bat -Skills a,b,c   (install only those)
+rem         install-skills.bat -DryRun         (preview only, no changes)
 cd /d "%~dp0"
 if not exist "install-skills.ps1" (
     echo [ERROR] install-skills.ps1 not found in %~dp0
     pause
     exit /b 1
 )
-powershell -NoProfile -ExecutionPolicy Bypass -File "install-skills.ps1"
+powershell -NoProfile -ExecutionPolicy Bypass -File "install-skills.ps1" %*
 echo.
 pause