Create issue templates for common bug report types.

[romainmenke]

Cases :

• plugin should output X but has output Y
• plugin breaks my build

Templates should focus on helping people gather debug info :

• what version are you using?
• what is the input and unexpected output
• can you reproduce it with npx <plugin-name> minimal-example.css?
• can you create a github repo with a minimal reproduction?
• ...

Just forcing a fixed format is not helpful imho.
So should still be possible to open a blank issue.