docs: add Electron 28 blog post

[ckerr]

This PR adds a new blog post for Electron 28. @electron/wg-releases, @electron/wg-outreach

Merge target: December 5th, after 28.0.0 releases.

⚠️ Do not merge until the following are completed ⚠️

• [x] update node, v8 and chromium versions from final chrome roll under Stack Changes section
• [x] edit link for M120 "New In Chrome" blog post
• [x] add a few bullets for New Features section
• [x] add any missing items in Breaking Changes section
• [x] update End of Support