docs(DEVELOPER.md) : Few minor enhancements

[UTSAVS26]

This change is required to improve the clarity and structure of the DEVELOPER.md file. By making minor enhancements, the file is now more user-friendly and provides clearer guidance for developers submitting pull requests. This helps ensure that contributors follow the correct process, including adding tests, updating changelogs, and ensuring proper documentation. These improvements streamline the contribution workflow and contribute to maintaining high-quality code and documentation standards in the project.

[CLAassistant]

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