Add MANTIS Free Tools to Infrastructure

[0xhimanshu]

Adding MANTIS Free Tools (https://mantiscore.ai/free-tools) to the Infrastructure section, slotted alphabetically between kics and Matano.

The toolkit bundles three free, browser-first security tools — a peer set to existing entries like Checkov / kics / tfsec / Terrascan / InfraScan:

• Dependency CVE scanner — lockfile in, OSV.dev CVE matches out (9 ecosystems: npm v1/v2/v3, yarn classic + berry, pnpm, pip, Pipfile.lock, Cargo, go.sum, Gemfile.lock, composer.lock).
• WAF detector — identifies which of 75+ WAF vendors sits in front of a URL.
• IaC misconfig scanner — Kubernetes, CloudFormation, Terraform, docker-compose, GitHub Actions. The rule engine runs entirely client-side; the file never crosses the network.

All three reachable at one URL, no signup required.

Per CONTRIBUTING.md:

• Single suggestion (one toolkit, one entry)
• Format: [Name](link) followed by description
• Slotted alphabetically into the existing Infrastructure section
• Description is succinct