single and double quote support in @import statement

[danielweck]

Fixes #163

[WesSouza]

You might want to be more strict to only match the same ending quote as the starting quote:

const re = new RegExp(/@import\s(['"])(\D+?)\1;/, 'gm');

And then replace 1 with 2 on line 87 given the new group.

const importFile = result?.[2];