[docs] Adding release notes for 5.3.1 and friends - #1750

Changed pages include:

• index.html - view
• versions.html - view
• search.html - view
• markdown-page.html - view
• 404.html - view
• docs/4.5.html - view
• general/community.html - view
• general/channels.html - view
• general/app_releases.html - view
• general/app.html - view

There are more changes not included in the list