Rationale: Opening links in the current tab is the default browser behavior.
Using `target="_blank"` on external links can lead to accessibility issues and override user preferences. It may also interfere with assistive technologies and expected browser behavior.
To maintain backward compatibility, this option is enabled by default (`true`), which adds `target="_blank"` to links.
- allow youtube urls to start with `www`
- use `strings.Builder` instead of a `bytes.Buffer`
- use a `strings.NewReader` instead of a `bytes.NewBufferString`
- sprinkles a couple of `continue` to make the code-flow more obvious
- inline calls to `inList`, and put their parameters in the right order
- simplify isPixelTracker
- simplify `isValidIframeSource`, by extracting the hostname and comparing it
directly, instead of using the full url and checking if it starts with
multiple variations of the same one (`//`, `http:`, `https://` multiplied by
``/`www.`)
- add a benchmark
