Revert "[Extension docs] Restore matches_about_blank documentation"

This reverts commit 50fd12992f2b31bf58599a5cc9ca2ce12ef93e35.

Reason for revert: This was already added in

Original change's description:
> [Extension docs] Restore matches_about_blank documentation
> The "matches_about_blank" section was inadvertently removed in
> b9b0b6c2f15330983573371f7c3d10185d5e5617. This patch restores the
> original documentation.
> Change-Id: Iaa38f5ea0bb019ff96619a8c8b49a43a44804432
> Reviewed-on:
> Commit-Queue: Rob Wu <>
> Reviewed-by: Devlin <>
> Cr-Commit-Position: refs/heads/master@{#639364},

Change-Id: I080414fac0f8dc2d4785d7129026794c696d9356
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-by: Rob Wu <>
Commit-Queue: Rob Wu <>
Cr-Commit-Position: refs/heads/master@{#639433}
1 file changed