Readme DevTools table: Sort, add hidden comment about sort on col 3

[mikehoffms]

https://github.com/MicrosoftEdge/Demos/edit/main/README.md

• Sort on col 3 (Repo directory) so Exploring the universe demo is not at bottom - can't find it.
• Add hidden comment above DevTools table, saying sort on col 3 (Repo directory).
• In edge-dev repo > DevTools > Samples, do same. (same table but different relative paths).
  https://learn.microsoft.com/microsoft-edge/devtools-guide-chromium/sample-code/sample-code#list-of-devtools-samples