fix changelog before release

Squashed commit of the following:

commit 754cc30
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Mon Nov 13 15:06:45 2023 +0200

    fix changelog before release

CHANGELOG.md

@@ -7,7 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 <!-- TODO: add @added tag to the files with specific version -->
 <!--       during new scriptlets or redirects releasing -->
 
-## [Unreleased]
+## [v1.9.91] - 2023-11-13
 
 ### Added
 
@@ -284,7 +284,7 @@ prevent inline `onerror` and match `link` tag [#276](https://github.com/AdguardT
     - `metrika-yandex-tag` [#254](https://github.com/AdguardTeam/Scriptlets/issues/254)
     - `googlesyndication-adsbygoogle` [#252](https://github.com/AdguardTeam/Scriptlets/issues/252)
 
-[Unreleased]: https://github.com/AdguardTeam/Scriptlets/compare/v1.9.83...HEAD
+[v1.9.91]: https://github.com/AdguardTeam/Scriptlets/compare/v1.9.83...v1.9.91
 [v1.9.83]: https://github.com/AdguardTeam/Scriptlets/compare/v1.9.72...v1.9.83
 [v1.9.72]: https://github.com/AdguardTeam/Scriptlets/compare/v1.9.70...v1.9.72
 [v1.9.70]: https://github.com/AdguardTeam/Scriptlets/compare/v1.9.62...v1.9.70