chore(tests): Relocate test_common.py into tests/ and update README

- Move `test_common.py` from project root into `tests/scraper/test_common.py` to align with test directory structure.
- Add a mention of running tests to README.

Author: RandomProgramm3r

README.md

@@ -9,11 +9,13 @@
 - [📋 Description](#-description)
 - [💻 Requirements](#-requirements)
 - [🚀 Project Installation](#-project-installation)
-	- [📂 Step 1: Clone the Repository](#-step-1-clone-the-repository)
+	- [🎶 Step 1: Clone the Repository](#-step-1-clone-the-repository)
 	- [🖥 Step 2: Create and activate a virtual environment](#-step-2-create-and-activate-a-virtual-environment)
 	- [🔃 Step 3: Installing Dependencies](#-step-3-installing-dependencies)
 
 - [⚙ Code Quality](#-code-quality)
+- [🧪 Testing](-testing)
+    - [📂 Run all tests](-run-all-tests)
 - [🧩 Usage](#-usage)
 - [🔨 Function Signature](#-function-signature)
 - [📤 Example](#-example)
@@ -90,6 +92,16 @@ ruff check --fix
 ruff format
 ```
 
+## 🧪 Testing
+
+### 📂 Run all tests
+
+##### To run the tests, execute the command
+```bash
+python3 -m unittest discover -v # Linux
+python -m unittest discover -v # Windows
+```
+
 
 ## 🧩 Usage
 ##### A market_scraper function retrieves pricing information for a specified item from the Steam Community Market.