Added Serplux SEO AI Agent

[Mitali2808]

Pull Request Template

1. Added Serplux - Serplux is a platform offering SEO, marketing, and content engineering tools—including AI-powered content automation, keyword research, and SEO audits to boost search visibility.
2. Added Category: Content Engineering - Which will have the products related to content writing, article creation, and content automation workflows to streamline and manage content production.

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• My changes were made in the resources folder, not in the auto-generated README.md file or db folder
• The resource is highly or exclusively related to programming and development
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[github-actions]

New resource link: https://serplux.com/