[docs] add contribute a blog post guide (#3180)

website/community/how-to-contribute/contribute-blog-post.md

@@ -0,0 +1,148 @@
+---
+title: Contribute a Blog Post
+sidebar_position: 1
+---
+
+# Contribute a Blog Post
+
+The [Apache Fluss blog](https://fluss.apache.org/blog) is a space for the community to share use cases, deep dives, release announcements, and project updates. Blog posts are authored by community members and reviewed by committers before being published.
+
+This guide walks you through submitting a blog post, from proposing the topic to getting it live on the site.
+
+Blog content lives in its own repository, [apache/fluss-blog](https://github.com/apache/fluss-blog), which is a Docusaurus 3 site built and deployed separately from the main documentation.
+
+## Propose Your Topic First
+
+Before writing, open an issue in [apache/fluss-blog](https://github.com/apache/fluss-blog/issues) describing the post you would like to write. Include:
+
+- A working title.
+- A short summary (a few sentences) of what you plan to cover.
+- Whether the post is a tutorial, case study, deep dive, release note, or something else.
+- A target length and any code samples or diagrams you plan to include.
+
+Getting feedback early avoids two people writing the same post and gives committers a chance to flag overlap with upcoming announcements.
+
+## Fork and Clone the Blog Repository
+
+```bash
+git clone https://github.com/<your-username>/fluss-blog.git
+cd fluss-blog
+npm install
+npm run start
+```
+
+The development server runs at `http://localhost:3000` with hot reload, so edits show up immediately.
+
+## Repository Layout
+
+```
+├── blog/                    # Blog content
+│   ├── YYYY-MM-DD-slug.md   # Blog posts (Markdown or MDX)
+│   ├── assets/              # Post-specific images and media
+│   ├── releases/            # Release announcement posts
+│   ├── static/              # Blog-related static files (for example, avatars)
+│   ├── authors.yml          # Author profiles
+│   └── tags.yml             # Tag definitions
+├── static/                  # Global static assets (logo, favicon)
+├── src/css/                 # Custom CSS
+├── docusaurus.config.ts     # Site configuration
+└── package.json
+```
+
+## Write the Post
+
+### 1. Create the Markdown file
+
+Add a new file under `blog/` using this naming convention:
+
+```
+blog/YYYY-MM-DD-my-post-slug.md
+```
+
+Use the date you expect the post to be merged and a short, URL-safe slug.
+
+### 2. Add frontmatter
+
+Every post must start with YAML frontmatter:
+
+```yaml
+---
+slug: my-post-slug
+title: "My Blog Post Title"
+date: YYYY-MM-DD
+authors: [your_key]
+tags: [apache-fluss]
+image: ./assets/my_post/banner.png
+---
+```
+
+- `slug` — URL path for the post (for example, `/blog/my-post-slug`).
+- `authors` — List of author keys defined in `blog/authors.yml`.
+- `tags` — List of tag keys defined in `blog/tags.yml`.
+- `image` — Optional cover image used for social sharing (Open Graph previews).
+
+### 3. Add images
+
+Place post-specific images in `blog/assets/<post_name>/` and reference them with relative paths from the post:
+
+```markdown
+![My Diagram](assets/my_post/diagram.png)
+```
+
+Keep images reasonably sized (compressed PNG or SVG) so the site stays fast to load.
+
+### 4. Add yourself as an author
+
+If this is your first post, add an entry to `blog/authors.yml`:
+
+```yaml
+your_key:
+  name: Your Name
+  title: Your Title
+  url: https://github.com/your-github
+  image_url: /avatars/your-avatar.png
+```
+
+Place your avatar image in `blog/static/avatars/`.
+
+### 5. Register new tags
+
+If your post uses a tag that does not yet exist, define it in `blog/tags.yml`:
+
+```yaml
+my-new-tag:
+  label: 'My New Tag'
+```
+
+Reuse existing tags when you can; only add new ones when none of them fit.
+
+## Preview and Build Locally
+
+```bash
+# Production build
+npm run build
+
+# Preview the production build locally
+npm run serve
+```
+
+Run the production build before opening a pull request; the Docusaurus build catches broken links, missing frontmatter fields, and other issues the dev server does not.
+
+## Submitting Your Post
+
+1. Commit your changes with a descriptive message:
+   ```bash
+   git add .
+   git commit -m "blog: add post on <topic>"
+   ```
+2. Push to your fork:
+   ```bash
+   git push origin your-branch-name
+   ```
+3. Open a pull request against [apache/fluss-blog](https://github.com/apache/fluss-blog), linking the topic issue you opened earlier.
+
+## Review and Publication
+
+Committers review the post for technical accuracy, tone, and fit with the broader project narrative. Expect light copy edits; substantive feedback comes first in the linked issue.
+
+Once the pull request merges into `main`, a CI pipeline automatically builds and publishes the new content to the [Apache Fluss website](https://fluss.apache.org/blog). No manual deploy step is required.