Updates to Security Get Started guides

[jmikell821]

Makes some enhancements to the Security GS guides.

[github-actions]

🔍 Preview links for changed docs

• solutions/security/get-started.md
• solutions/security/get-started/get-started-cloud-security.md
• solutions/security/get-started/get-started-detect-with-siem.md
• solutions/security/get-started/get-started-endpoint-security.md
• solutions/security/get-started/quickstarts.md

[benironside]

Good work, nice to see this guide getting some love. Left some suggestions for your consideration, I hope they're helpful!