Add simple guidelines & instructions for blog contribution

Modeled after knative's blog guidelines.
https://github.com/knative/docs/blob/master/blog/README.md

PiperOrigin-RevId: 346905713

website/blog/README.md

@@ -0,0 +1,62 @@
+# gVisor blog
+
+The gVisor blog is owned and run by the gVisor team.
+
+## Contact
+
+Reach out to us on [gitter](https://gitter.im/gvisor/community) or the
+[mailing list](https://groups.google.com/forum/#!forum/gvisor-users) if you
+would like to write a blog post.
+
+## Submit a Post
+
+Anyone can write a blog post and submit it for review. Purely commercial content
+or vendor pitches are not allowed. Please refer to the
+[blog guidelines](#blog-guidelines) for more guidance about content is that
+allowed.
+
+To submit a blog post, follow the steps below.
+
+1.  [Sign the Contributor License Agreements](https://gvisor.dev/contributing/)
+    if you have not yet done so.
+1.  Familiarize yourself with the Markdown format for the
+    [existing blog posts](https://github.com/google/gvisor/tree/master/website/blog).
+1.  Write your blog post in a text editor of your choice.
+1.  (Optional) If you need help with markdown, check out
+    [StakEdit](https://stackedit.io/app#) or read
+    [Jekyll's formatting reference](https://jekyllrb.com/docs/posts/#creating-posts)
+    for more information.
+1.  Click **Add file** > **Create new file**.
+1.  Paste your content into the editor and save it. Name the file in the
+    following way: *[BLOG] Your proposed title* , but don’t put the date in the
+    file name. The blog reviewers will work with you on the final file name, and
+    the date on which the blog will be published.
+1.  When you save the file, GitHub will walk you through the pull request (PR)
+    process.
+1.  Send us a message on [gitter](https://gitter.im/gvisor/community) with a
+    link to your recently created PR.
+1.  A reviewer will be assigned to the pull request. They check your submission,
+    and work with you on feedback and final details. When the pull request is
+    approved, the blog will be scheduled for publication.
+
+### Blog Guidelines {#blog-guidelines}
+
+#### Suitable content:
+
+-   **Original content only**
+-   gVisor features or project updates
+-   Tutorials and demos
+-   Use cases
+-   Content that is specific to a vendor or platform about gVisor installation
+    and use
+
+#### Unsuitable Content:
+
+-   Blogs with no content relevant to gVisor
+-   Vendor pitches
+
+## Review Process
+
+Each blog post should be approved by at least one person on the team. Once all
+of the review comments have been addressed and approved, a member of the team
+will schedule publication of the blog post.

website/blog/index.html

@@ -20,3 +20,8 @@ pagination:
 {% if paginator.total_pages > 1 %}
 {% include paginator.html %}
 {% endif %}
+
+<hr>
+
+If you would like to contribute to the gVisor blog check out the
+<a href="https://github.com/google/gvisor/tree/master/website/blog">instructions</a>.