Add v14 release announcement blog post

[flanakin]

🛠️ Description

Drafts the FinOps toolkit 14 announcement for the FinOps Tech Community blog. Covers four featured sections:

1. Build your own FinOps agent in Copilot Studio — the new agent template that connects to hub Data Explorer via the Kusto Query MCP Server.
2. Recommendations come to FinOps hubs — Azure Advisor + custom Resource Graph query ingestion into the Recommendations dataset.
3. A simpler hub deployment experience — the consolidated hub mode radio group and conditional setting visibility.
4. Preview: commitment discount eligibility data — the new pre-computed open data dataset, framed as preview with an explicit ask for feedback.

Plus the standard "Other new and noteworthy" roll-up grouped by tool, "What's next", and a social media appendix with {{POST_URL}} placeholders for LinkedIn, Twitter/X, and internal channels.

Doc links use GitHub dev branch URLs since the corresponding MS Learn pages won't be published by the time the post goes out. Update them to learn.microsoft.com URLs before publishing.

Depends on #2117 for the announce/ folder structure.

Fixes #

📋 Checklist

🔬 How did you test this change?

• 🤏 Lint tests
• 🤞 PS -WhatIf / az validate
• 👍 Manually deployed + verified
• 💪 Unit tests
• 🙌 Integration tests

📦 Deploy to test?

• Hubs + ADX (managed)
• Hubs + Fabric (manual)
• Hubs (manual)
• Hubs (no data)
• Workbooks
• Alerts

🙋‍♀️ Do any of the following that apply?

• 🚨 This is a breaking change.
• 🤏 The change is less than 20 lines of code.

📑 Did you update `docs/changelog.md`?

• ✅ Updated changelog (required for `dev` PRs)
• ➡️ Will add log in a future PR (feature branch PRs only)
• ❎ Log not needed (small/internal change)

📖 Did you update documentation?

• ✅ Public docs in `docs` (required for `dev`)
• ✅ Public docs in `docs-mslearn` (required for `dev`)
• ✅ Internal dev docs in `docs-wiki` (required for `dev`)
• ✅ Internal dev docs in `src` (required for `dev`)
• ➡️ Will add docs in a future PR (feature branch PRs only)
• ❎ Docs not needed (small/internal change)

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Adds the draft FinOps toolkit v14 release announcement post for the Tech Community blog, covering the headline features (Copilot Studio hub agent template, recommendations ingestion, simplified hub deployment UI, and preview commitment discount eligibility dataset) plus “other noteworthy updates” and social media copy.

Changes:

• Introduces a new v14 announcement markdown draft under announce/2026/.
• Includes sectioned release narrative plus a “What’s next” and social media appendix with {{POST_URL}} placeholders.