feat!: front-matter language -> lang

src/content/config.ts

@@ -9,7 +9,7 @@ const postsCollection = defineCollection({
     image: z.string().optional().default(''),
     tags: z.array(z.string()).optional().default([]),
     category: z.string().optional().default(''),
-    language: z.string().optional().default(''),
+    lang: z.string().optional().default(''),
 
     /* For internal use */
     prevTitle: z.string().default(''),