issues: Improve issues templates

Here are some files to get inspiration from: https://github.com/vuejs/core/tree/35785f3cd7bd86cbec3f8324022491da2d088b61/.github/ISSUE_TEMPLATE

They use the [Issue form](https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/configuring-issue-templates-for-your-repository#creating-issue-forms) beta feature.  
We can use it too.