Use new GitHub Issue templates

[matz3]

There is now the option to have multiple templates (e.g. for bug report and feature request).

https://help.github.com/articles/about-issue-and-pull-request-templates
https://help.github.com/en/articles/creating-issue-templates-for-your-repository

[RandomByte]

Good example for usage of these templates: https://github.com/electron/electron/issues/new/choose