docs: clarify UIManager LayoutAnimation scope and New Architecture behaviour. - #5262

Changed pages include:

• index.html - view
• 404.html - view
• blog.html - view
• releases.html - view
• search.html - view
• showcase.html - view
• versions.html - view
• architecture/bundled-hermes.html - view
• architecture/fabric-renderer.html - view
• architecture/glossary.html - view

There are more changes not included in the list