chore(ui): improve navigation and buttons placement - #8608

Changed pages include:

• index.html - view
• 404.html - view
• advanced/index.html - view
• backends/index.html - view
• faq/index.html - view
• features/index.html - view
• getting-started/index.html - view
• index.print.html - view
• index.searchindex.html - view
• installation/index.html - view

There are more changes not included in the list