Refine kernel tuning 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
• restructure the kernel tuning guide to emphasize inspection workflows, persistence best practices, IO scheduler selection, and swap management
• replace the legacy file descriptor note with a dedicated process-and-file limits reference and remove the obsolete plain text file

Testing

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

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

[Copilot]

Pull Request Overview

This pull request converts legacy plain-text documentation into Markdown format and refines kernel tuning guides with expanded persistence instructions, process limit diagnostics, and additional references to kernel ceilings.

• Migrated all .txt cheat sheets (LEMP, SSH, NTP, firewall, Docker, backup, Ansible) to .md format with consistent metadata and fenced code blocks
• Expanded kernel tuning documentation with new inspection workflows, sysctl persistence patterns, I/O scheduler selection, and swap management
• Introduced dedicated process and file descriptor limit guide with detailed soft/hard/kernel ceiling explanations
• Added pre-commit hooks, pymarkdown configuration, and GitHub Actions workflow for Markdown linting

Reviewed Changes

Copilot reviewed 64 out of 64 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
Tunning kernel/tuning_kernel.md	New comprehensive kernel tuning overview with inspection commands and persistence best practices
Tunning kernel/process_and_file_limits.md	New dedicated guide for process limits, file descriptors, and kernel ceilings
Tunning kernel/Tuning Kernel.txt	Removed legacy plain-text kernel tuning file
Tunning kernel/Max file descriptor	Removed legacy plain-text file descriptor guide
Web Services/LEMP-*.md	Converted LEMP stack installation guides to Markdown
SSH/SSH Overview.md	Converted SSH hardening guide to Markdown
NTP/NTP_basic.md	Converted NTP configuration guide to Markdown
Firewall/IPtables_basic.md	Converted iptables configuration guide to Markdown
Docker/*.md	Converted multi-part Docker tutorial series to Markdown
Backup/*.md	Converted backup script documentation to Markdown
README.md	Updated repository overview with Markdown linting instructions
.pre-commit-config.yaml, .pymarkdown.json, .github/workflows/markdown-lint.yml	Added linting infrastructure

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[Copilot]

The sed pattern uses complex quoting and group references that may confuse readers. Consider adding an explanatory comment above this line describing that it comments out all swap entries in /etc/fstab by prepending a # to lines matching the pattern.

Suggested change

	sudo swapoff -a
	sudo swapoff -a
	# Comment out all swap entries in /etc/fstab by prepending a '#'

[Copilot]

The date format is inconsistent with the format used in other files in this PR. Other files use YYYY-MM-DD format (e.g., '2017-11-14'), while this file uses YYYY-DD-MM format ('2017-04-12'). For consistency, consider standardizing on YYYY-MM-DD throughout the repository.