style: 配置站点副标题/Logo/头像并整理图片资源

- 启用首页副标题（打字机效果）
- 修复 nav.logo 被 theme_config 空值覆盖导致不显示的问题
- 头像改为 /images/core.jpg
- 重做 logo：去白底并圆形内部填白
- 新增 Markdown 使用指南，整理文章图片到对应目录

package.json

@@ -3,11 +3,22 @@
   "version": "0.0.0",
   "private": true,
   "scripts": {
-    "build": "hexo generate",
+    "start": "powershell -ExecutionPolicy Bypass -File ./tools/blog.ps1 preview",
     "clean": "hexo clean",
-    "preview": "bash scripts/blog.sh preview",
-    "deploy": "bash scripts/blog.sh deploy",
-    "server": "hexo server"
+    "build": "hexo generate",
+    "server": "hexo server",
+    "preview": "powershell -ExecutionPolicy Bypass -File ./tools/blog.ps1 preview",
+    "deploy": "powershell -ExecutionPolicy Bypass -File ./tools/blog.ps1 deploy",
+    "win:clean": "powershell -ExecutionPolicy Bypass -File ./tools/blog.ps1 clean",
+    "win:build": "powershell -ExecutionPolicy Bypass -File ./tools/blog.ps1 build",
+    "win:server": "powershell -ExecutionPolicy Bypass -File ./tools/blog.ps1 server",
+    "win:preview": "powershell -ExecutionPolicy Bypass -File ./tools/blog.ps1 preview",
+    "win:deploy": "powershell -ExecutionPolicy Bypass -File ./tools/blog.ps1 deploy",
+    "linux:clean": "bash ./tools/blog.sh clean",
+    "linux:build": "bash ./tools/blog.sh build",
+    "linux:server": "bash ./tools/blog.sh server",
+    "linux:preview": "bash ./tools/blog.sh preview",
+    "linux:deploy": "bash ./tools/blog.sh deploy"
   },
   "hexo": {
     "version": "8.1.2"