Fix/short meta descriptions

[omkar-cometchat]

Description

This PR fixes SEO meta description issues reported in the short meta description audit.

Many affected pages had missing, very short, or generic descriptions. Some descriptions were only a few words long, used basic “Overview” style wording, or did not clearly mention
CometChat, the relevant product area, platform, framework, SDK, UI Kit, REST API, or Calls version.

The goal was to bring descriptions closer to the recommended SEO range of roughly 100-150 characters where useful, without over-optimizing pages that were already clear and specific.

High-level categories updated:

• SDK docs
• UI Kit docs
• Calls docs
• REST API docs
• Chat Builder docs
• Notifications docs
• Fundamentals docs
• Moderation docs
• On-Premise Deployment docs
• AI Agents and Articles pages

Changes made:

• Added missing meta descriptions to current/latest docs pages.
• Expanded very short descriptions that were too generic to be useful in search previews.
• Made descriptions more specific to the actual page content.
• Added platform/framework specificity where needed, such as Android, iOS, Flutter, React, React Native, Angular, Vue, JavaScript, Next.js, Astro, and React Router.
• Clarified product area names such as CometChat SDK, UI Kit, Calls SDK v5, REST API, Notifications, Moderation, Chat Builder, and On-Premise Deployment.
• Updated REST API descriptions to describe exact endpoint behavior more clearly.
• Updated Calls docs descriptions across current Calls SDK v5 pages.
• Updated current UI Kit descriptions across Flutter, iOS, Android, React, React Native, Angular, and Vue.
• Updated current SDK descriptions across Android, iOS, Flutter, JavaScript, React Native, and Unreal where needed.
• Left already-clear descriptions unchanged, even when slightly short.
• Excluded versioned/legacy docs unless they were part of the current cleanup scope.
• Classified stale URLs separately where pages were removed or restructured.

Related Issue(s)

N/A

Type of Change

• Documentation correction/update
• New documentation
• Improvement to existing documentation
• Typo fix
• Other (please specify)

Checklist

• I have read the ../CONTRIBUTING.md document
• My branch name follows the naming convention (.github/branch-naming-convention.md)
• My changes follow the documentation style guide
• I have checked for spelling and grammar errors
• All links in my changes are valid and working
• My changes are accurately described in this pull request

Additional Information

Versioned/legacy pages and stale URLs were not edited unless they were part of the current cleanup scope.

Screenshots (if applicable)

N/A