Migrate from deprecated node-sass to Dart Sass and update dependencies (#33)

* Initial plan

* Update packages to stable versions and migrate from node-sass to sass (Dart Sass)

Co-authored-by: warengonzaga <15052701+warengonzaga@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: warengonzaga <15052701+warengonzaga@users.noreply.github.com>

Author: Copilot

demo/assets/css/fork-corner.min.css

@@ -4,7 +4,7 @@
  * Version: 2.0.1
  * Github: https://github.com/WarenGonzaga/fork-corner
  * Licensed under The MIT License: http://opensource.org/licenses/MIT
- * Copyright (c) 2021 Waren Gonzaga
+ * Copyright (c) 2026 Waren Gonzaga
  *
  * Facebook: @warengonzagaofficial
  * Twitter: @warengonzaga

demo/assets/js/fork-corner.js

@@ -4,7 +4,7 @@
  * Version: 2.0.1
  * Github: https://github.com/WarenGonzaga/fork-corner
  * Licensed under The MIT License: http://opensource.org/licenses/MIT
- * Copyright (c) 2021 Waren Gonzaga
+ * Copyright (c) 2026 Waren Gonzaga
  *
  * Facebook: @warengonzagaofficial
  * Twitter: @warengonzaga