Clarify kernel tuning limit documentation

[nduytg]

Summary

• rename the kernel tuning markdown files to use an underscore naming pattern
• expand the kernel tuning overview with additional persistence guidance and references to kernel ceilings
• deepen the process and file descriptor limit guide with detailed inspections of soft, hard, and kernel limits

Testing

• ⚠️ pre-commit run --all-files (command not found in container)

---

https://chatgpt.com/codex/tasks/task_e_68ef8e35203083339da9a266f9a2f3f6

[Copilot]

Pull Request Overview

This pull request migrates the repository from plain-text documentation to Markdown format and introduces modern tooling. All legacy .txt files are replaced with structured .md files that follow consistent formatting guidelines. The kernel tuning documentation is expanded with additional guidance on persistence, limit types, and cross-references. Pre-commit hooks and a GitHub Actions workflow enforce Markdown linting standards across the codebase.

Key changes:

• Converted all .txt files to .md with standardized metadata, headings, and code blocks
• Renamed kernel tuning files from hyphenated to underscore naming (Tuning Kernel.txt → tuning_kernel.md)
• Added comprehensive kernel tuning guides covering soft/hard/kernel limits, I/O schedulers, swap, and file descriptor ceilings
• Introduced linting infrastructure (.pre-commit-config.yaml, .pymarkdown.json, GitHub Actions workflow)

Reviewed Changes

Copilot reviewed 64 out of 64 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
README.md	Expanded to describe repository layout, linting, and local development workflow
Tunning kernel/tuning_kernel.md	New comprehensive kernel tuning overview with persistence instructions and limit references
Tunning kernel/process_and_file_limits.md	New deep-dive on soft, hard, and kernel-wide file descriptor limits
Web Services/LEMP-*.md	Converted LEMP installation guides to Markdown with improved structure
SSH/SSH Overview.md, SSH/*_result.md	Migrated SSH hardening and audit reports to Markdown
Docker/*-Guide-*.md	Converted multi-part Docker tutorials to Markdown
Backup/backup-*.md	Migrated backup scripts and rotation logic to Markdown
High Availability/keepalived-nginx.md	Converted HA configuration to Markdown
Load Balancing/*.md	Migrated NGINX tuning and load balancing guides to Markdown
Firewall/IPtables_basic.md, NTP/NTP_basic.md, Automation/Ansible-Beginner.md, Utils/X11 on CentOS.md	Converted platform-specific guides to Markdown
.pre-commit-config.yaml, .pymarkdown.json, .github/workflows/markdown-lint.yml	Added linting infrastructure

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}