Fix broken Azure Gov deploy badge and workbook image link in readme for Cybersecurity Maturity Model Certification (CMMC) 2.0

[v-kasghosh]

Change(s)

• Bumped the Cybersecurity Maturity Model Certification (CMMC) 2.0 solution version from
  3.1.0 → 3.1.1 in Data/Solution_CybersecurityMaturityModelCertification(CMMC)2.0.json
• readme.md: replaced the dead Deploy to Azure Gov badge alias
  https://aka.ms/deploytoazuregovbutton with https://aka.ms/deploytoazuregovernbutton
• readme.md: corrected the broken Workbook Overview image reference

Reason for Change(s)

• The aka.ms/deploytoazuregovbutton short link no longer resolves to the Azure Government deploy
  badge (it falls back to a search page), so the "Deploy to Azure Gov" button rendered as a broken
  image in the solution readme. aka.ms/deploytoazuregovernbutton resolves to the correct badge SVG.
  Only the badge image URL changed — the underlying portal.azure.us deployment target link is
  untouched, so deployment behavior is unaffected.
• The Workbook Overview image URL pointed at a filename that does not exist in
  Workbooks/Images/, leaving a broken image in the readme.

Version updated

Yes — solution version 3.1.0 → 3.1.1. No analytic rule / detection logic was modified.

Testing Completed

Yes — documentation and metadata only; no KQL, workbook, connector or playbook logic changed.
Verified that the new badge URL resolves to the Azure Gov deploy badge, that the deployment target
URL is unchanged, and that the referenced workbook image resolves.

Checked that the validations are passing and have addressed any issues that are present

Yes