Categorize issue template

[yussufsh]

This change will present two buttons when Issues page is open. Users don't need to copy the title text. They can start reporting from the selected issue template.

Example:

Please make sure that you follow instructions from CONTRIBUTING

Specially:

• Check if all tests pass, see TESTING for deatils.
• Make sure you've added test coverage for new features/metrics.
• Make sure you have updated documentation.
• If you added a new metric, please make sure you have been following instructions about adding new metric.