misc: revamped gateway docs

[sheensantoscapadngan]

Description 📣

This PR improves gateway docs to be easier to follow. The PR also adds CLI docs for relay systemd install and uninstall

Type ✨

• Bug fix
• New feature
• Improvement
• Breaking change
• Documentation

Tests 🛠️

# Here's some code block to paste some code snippets

---

• I have read the contributing guide, agreed and acknowledged the code of conduct. 📝

[maidul98]

🎉 Snyk checks have passed. No issues have been found so far.

✅ security/snyk check is complete. No issues have been found. (View Details)

[greptile-apps]

Greptile Summary

This PR comprehensively revamps the Infisical Gateway documentation to improve usability and clarity. The changes restructure the existing documentation from a single overwhelming guide into a well-organized, multi-page structure that follows a logical user journey.

Key improvements include:

Restructured Navigation: The documentation is now organized into distinct sections - overview, deployment, networking requirements, and security - allowing users to find relevant information more easily. The docs.json file reflects this improved organization with a more logical page ordering.

Enhanced Overview: The overview.mdx file has been transformed from a dense all-in-one guide into a focused introduction that clearly explains the concepts of Gateways and Relay servers, their differences, and use cases before directing users to specialized implementation guides.

New Comprehensive Deployment Guide: A new deployment.mdx file provides detailed step-by-step instructions for various deployment methods including Linux systemd services, Kubernetes Helm charts, and development environments. It includes proper warnings about Gateway v2 migration requirements and authentication configurations.

Expanded Networking Documentation: The networking.mdx file now includes detailed relay server requirements, cloud provider-specific firewall configuration examples (AWS, GCP, Azure), performance considerations, and enhanced FAQ sections.

Improved Security Documentation: The security.mdx file has been restructured with corrected technical diagrams, comprehensive security best practices, compliance considerations, and troubleshooting guidance.

Enhanced CLI Documentation: The relay.mdx CLI documentation adds comprehensive coverage of the new infisical relay systemd command for managing relay services as systemd services.

These changes reflect a documentation maturation effort, moving from basic instructions to comprehensive enterprise-ready guidance that addresses common deployment scenarios and reduces support burden.

PR Description Notes:

• The PR description checkboxes are not filled out (Type and acknowledgment sections remain unchecked)
• The Tests section contains only placeholder content

Confidence score: 5/5

• This PR is extremely safe to merge with virtually no risk of production issues
• Score reflects that this is purely documentation improvement with no functional code changes or breaking modifications
• No files require special attention as all changes enhance user experience without affecting system functionality

Context used:

Context - When naming sections in documentation, use clear and descriptive titles that reflect the functionality to avoid confusion among users. (link)
Context - Use 'email auth' instead of 'direct credential login' in documentation to provide clearer terminology for users. (link)

_{6 files reviewed, no comments}

_{Edit Code Review Bot Settings | Greptile}

[maidul98]

since we won't mention instance type deployment, we'll need to write how to deploy a gateway for org scoped. i have left that black since you are working on the feature as we speak