fix: remove unused ogImage size validation (#462)

* fix: remove unused ogImage size validation

Validation of `ogImage` field in blog collection
causes unintentional broken og images after the build.
Removing the validation solve the issue.

* docs: update docs for ogImage path

* chore: update asset

src/content.config.ts

@@ -13,12 +13,7 @@ const blog = defineCollection({
       featured: z.boolean().optional(),
       draft: z.boolean().optional(),
       tags: z.array(z.string()).default(["others"]),
-      ogImage: image()
-        .refine(img => img.width >= 1200 && img.height >= 630, {
-          message: "OpenGraph image must be at least 1200 X 630 pixels!",
-        })
-        .or(z.string())
-        .optional(),
+      ogImage: image().or(z.string()).optional(),
       description: z.string(),
       canonicalURL: z.string().optional(),
       editPost: z