Update README.md

Author: namvdo

challenges/wc-command/README.md

@@ -1,12 +1,44 @@
 # wc-command
+**Author:** [namvdo](https://github.com/namvdo)
+## Overview
 
-## Given By 
+`wc-command` is a program that implements a simple command-line utility for counting words in a text file and the occurrences of a specific word. The program is designed to leverage parallel processing for improved performance, making it suitable for handling large text files efficiently.
 
-## Topics
+## Features
+
+- Count the total number of words in a text file.
+- Count the occurrences of a specified word in a text file.
+
+## Relevant Background Knowledge
+To effectively tackle this problem, it is important to have a basic understanding of the following concepts:
+1. **Rust Syntax**: Familiarity with Rust's syntax, including functions, control flow, and data structures.
+2. **Ownership and Borrowing**: Understanding Rust’s ownership model is crucial for memory safety and efficient resource management.
+3. **Parallel Processing**: Knowledge of threading in Rust to leverage concurrency for performance improvements.
+4. **Memory Mapping**: Skills in using memory-mapped files for efficient file reading.
+5. **Command-Line Arguments**: Understanding how to parse command-line arguments for user input.
 
 ## Main Functions
 
-## Example Output
+1. **`read_file_as_string(file_path: &str) -> String`**  
+   Reads a file and returns its content as a `String`.
 
-## Usage Example
+2. **`count_words(text: &str) -> usize`**  
+   Counts the total number of words in the provided text.
 
+3. **`count_word_occurrences(text: &str, word: String) -> usize`**  
+   Counts the occurrences of a specific word in the provided text.
+
+4. **`count_in_paralell<F>(text: &str, count_fn: F) -> usize`**  
+   A generic function that processes text in parallel using the provided counting function.
+
+## Usage Example
+First, compile the program:
+```bash
+cd challenges/wc-command && cargo build
+cargo run -- rccwc -w /path/to/the/input/file.txt
+cargo run -- rccwc -wo rust /path/to/the/input/file.txt
+```
+Run test test:
+```bash
+cargo test
+```