Transparent Modification of HTTP Requests

# Introduction

In this project, you will learn how to implement a transparent modification of HTTP requests using Go's `http.RoundTripper` interface. You will create a custom HTTP transport that calculates the MD5 hash of the request body and adds it to the request header as the "X-Md5" field.

## 👀 Preview

$ /usr/local/go/bin/go test
PASS
ok      md5transport    0.004s

## 🎯 Tasks

In this project, you will learn:

- How to encapsulate the `http.RoundTripper` interface to perform custom operations on HTTP requests and responses.
- How to calculate the MD5 hash of the request body and add it to the request header.
- How to reset the request body after calculating the MD5 hash to maintain the original request state.

## 🏆 Achievements

After completing this project, you will be able to:

- Understand the concept of transparent modification of HTTP requests in Go.
- Implement custom HTTP transport layers that can perform various operations on requests and responses.
- Apply the knowledge to enhance your own applications with additional functionality, such as authentication, logging, or request/response manipulation.