refactor: enhance theme configuration and path handling

- Update config.ts with more descriptive comments and simplified settings
- Remove about page content section
- Add new path utility functions for localization and page type detection
- Introduce SiteTitle component for mobile post page navigation
- Modify Header and Layout components to use new path utilities
- Adjust title spacing and font sizes
- Update VSCode settings with new dictionary words

src/types/index.d.ts

@@ -33,7 +33,7 @@ export interface ThemeConfig {
     locale: typeof langPath[number]
     moreLocale: typeof langPath[number][]
     fontStyle: 'sans' | 'serif'
-    titleSpace: 1 | 2 | 3 | 4
+    titleSpace: 1 | 2 | 3
   }
 
   comment?: {
@@ -83,12 +83,6 @@ export interface ThemeConfig {
     customUmamiAnalyticsURL?: string
     customUmamiAnalyticsJS?: string
   }
-
-  about: {
-    [key in ThemeConfig['global']['locale']]: string
-  } & {
-    [key in ThemeConfig['global']['moreLocale'][number]]?: string
-  }
 }
 
 export default ThemeConfig