[Forwardport] Update issue templates for Magento 2 GitHub project

[mage2pratik]

Original Pull Request

#17817

Description

This pull request adds more templates to the Issue Reporting section of the GitHub. New templates are targeting a broader scope of possible problems and proposed descriptions are aimed at simplifying future fixes.

Proposed set of templates currently cover:

• Bug report (same, default bug report template)
• Developer experience issue (Issues related directly to the application design and architecture, for example: modularity, extensibility, ability to customize, etc.)
• Feature requests (clarifies, that separate project is used for that, requests minimum input and description)

Fixed Issues (if relevant)

N/A

Manual testing scenarios

N/A

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[magento-engcom-team]

Hi @mage2pratik. Thank you for your contribution
Here is some useful tips how you can test your changes using Magento test environment.
Add the comment under your pull request to deploy test or vanilla Magento instance:

• @magento-engcom-team give me test instance - deploy test instance based on PR changes
• @magento-engcom-team give me {$VERSION} instance - deploy vanilla Magento instance

For more details, please, review the Magento Contributor Assistant documentation

[magento-engcom-team]

Hi @mage2pratik. Thank you for your contribution.
We will aim to release these changes as part of 2.3.0.
Please check the release notes for final confirmation.