Add bash language specification to code blocks in Hausa translation

[Roshanjossey]

🎯 Goal
Add missing language specification to code blocks in the Hausa translation of the README to improve syntax highlighting and readability.

🐞 Problem
The Hausa translation has code blocks without language specifications (just instead ofbash), which prevents proper syntax highlighting and makes the commands less readable.

💡 What needs to be done
Add bash language specification to all code blocks containing shell commands. You can find the file at:
https://github.com/firstcontributions/first-contributions/blob/main/docs/translations/README.hau.md

What needs to be changed:

• Find all code blocks that contain shell commands (git commands, terminal commands)
• add bash language specification to these code blocks

Example of what needs to be fixed:

Currently without language specification
```
git clone git@github.com:this-is-you/first-contributions.git
```

Should be (with bash language specification)
```bash
git clone git@github.com:this-is-you/first-contributions.git
```

Important

Please only address one issue in a PR.
Let's make it possible for more people to solve issues here.

📋 Steps to solve the problem

• Comment below about what you've started working on.
• Find all code blocks in the Hausa README that contain shell/git commands
• Add bash language specification to these code blocks
• Ensure syntax highlighting works properly
• Add, commit, push your changes.
• Submit a pull request and add this in comments - 'Resolves #'
• Ask for reviews in comments section of pull request.
• Celebrate your contribution to this project. 🎉

[Pranav-0440]

I’ve completed the changes for adding bash syntax highlighting to the Hausa README.