[Site]: Blog posts front-matter / layout does not support rendering multiple authors

### Current State

### Current Behavior
When a blog post has multiple authors configured in its markdown front-matter metadata, the website layout/framework only renders the first author name, completely dropping the second author.

For example, on the **Release Apache APISIX 3.16.0** blog post, the page metadata or Git history indicates there are two co-authors. However, the published web page only displays:
`Apr 7, 2026 · Abhishek Choudhary · 8 min read`

The second author's name and profile link are omitted due to a limitation in the current theme/layout engine.

### Link to the affected page
https://apisix.apache.org/blog/2026/04/07/release-apache-apisix-3.16.0/

### Desired State

**Description of the change you are proposing**:

### Expected Behavior
The blog post layout component should be updated to check if the `author` field is an array or if multiple author keys exist. It should cleanly render all contributing authors separated by commas or in a list (e.g., `Author A, Author B`), ensuring proper credit is given to all community contributors.

### Would you like to fix this issue?

No. Please assign another contributor

Start by locating the blog post layout or theme component that renders the metadata for the affected Release Apache APISIX 3.16.0 page. Reproduce the page with multiple authors in front matter and trace how the author value is read. Done means the published layout displays every configured author, including each author's profile link where available.

Written by the indexing model from the issue text.