Enable community blog submissions on GitHub Pages (Docsify)

[Copilot]

Blog Post Submission

Summary

This PR adds a first-class community blog flow to the existing Docsify/GitHub Pages site: contributors submit markdown posts via PR, maintainers review, and merged posts are published automatically. It introduces blog structure, contributor policy, review ownership, and CI validation for metadata/link quality.

• Blog surface area

  • Added blog/README.md (landing page/index), blog/_template.md (required front matter schema), and blog/posts/2026-06-24-community-welcome.md (seed post).
  • Added Community Blog entry to _sidebar.md for site navigation.

• Contributor + moderation model

  • Extended CONTRIBUTING.md with a dedicated “Submit a Blog Post” section (filename convention, required metadata, scope/quality expectations).
  • Added .github/PULL_REQUEST_TEMPLATE/blog_post.md to standardize submission quality and author self-checks.
  • Added .github/CODEOWNERS rule for /blog/** to enforce maintainer review routing.

• Automated quality gate

  • Added .github/workflows/blog-post-validation.yml to validate changed blog/posts/*.md files on PRs.
  • Enforces required front matter keys, date format + non-future dates, and verifies local markdown links resolve.
  • Uses explicit minimal workflow token permissions.

---
title: "Your Post Title"
author: "Your Name"
date: "YYYY-MM-DD"
tags:
  - devops
summary: "One or two sentence summary."
---

Checklist

• I added my post under blog/posts/ with filename format YYYY-MM-DD-short-title.md
• I used the metadata schema from blog/_template.md (title, author, date, tags, summary)
• My post is original and relevant to the 90DaysOfDevOps community topics
• I verified local markdown links and image paths
• I have read and followed CONTRIBUTING.md

[github-actions]

Our team will soon review your PR. Thanks @Copilot :)

[github-actions]

Hello there, thanks for opening your first Pull Request. Someone will review it soon. Welcome to the #90DaysOfDevOps community!

[github-actions]

Thank you @Copilot for taking out your valuable time in order to contribute to our project. Looking forward for more such amazing contributions :)