Creating a comprehensive README for your GitHub repository is crucial for helping users understand your code, its purpose, and how to use it effectively. Below, I've provided a template for your README based on your code and the options you've implemented. Remember to replace placeholders with actual content:

This is a versatile text search tool developed in Rust that allows you to search for specific patterns in files and directories. It offers various search options, including case-insensitive searching, non-matching results, and the ability to search within directories.

• Features
• Prerequisites
• Usage
• Configuration Options
• Examples
• License

• Search for patterns in files and directories.
• Option for case-insensitive searching.
• Find files that do not match the specified pattern.
• Search within directories and their contents.
• Define search depth within directories.
• Parallel searching using multiple threads.
• Utilizes the regex and walkdir crates.
• Easy-to-use command-line interface.

Before using this tool, ensure you have the following prerequisites:

• Rust and Cargo: Installation Instructions
• Git: Installation Instructions

Clone the repository and build the tool using the following commands:

git clone https://github.com/yourusername/text-search-tool.git
cd text-search-tool
cargo build --release

Run the tool with the desired options:

cargo run [OPTIONS] PATTERN [FILE/DIRECTORY]

The tool supports various options that customize your search. These options are specified as environment variables:

• IC: Perform case-insensitive searching.
• NON: Find files and lines that do not match the pattern.
• DIR: Search inside directories and find only files with the pattern.
• IN: Search inside files found in directories.
• DPT:[1..n]: Specify the search depth through directories (default is 1).
• TH: Enable parallel searching.
• NT:[1..n]: Specify the number of threads for parallel searching (default is 6).

Search for the pattern "example" in a file:

cargo run example path/to/yourfile.txt

Perform a case-insensitive search for "example" in a file:

IC=1 cargo run example path/to/yourfile.txt

Find lines in a file that do not contain "example":

NON=1 cargo run example path/to/yourfile.txt

Search for files containing "example" within a directory:

DIR=1 cargo run example path/to/yourdirectory

Search inside files found in directories:

IN=1 cargo run example path/to/yourdirectory

Enable parallel searching with a specified number of threads:

TH=1 NT:4 cargo run example path/to/yourdirectory