Added Apache Jmeter's Pull Request template

[niranjanghule]

Please ensure your pull request adheres to the following guidelines:

• Use the following format: * [owner/repo](link)
• Link additions should be added to the bottom of the relevant category.
• New categories or improvements to the existing categorization are welcome.
• Search previous suggestions before making a new one, as yours may be a duplicate.
• Sort by alphabetical order

Thanks for contributing!