Improve Bootstrap link style regex

[coliff]

The regex correctly works on this:

<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.css" rel="stylesheet" />

but not:

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.css" />

Can we improve the regex to account for that?