Autolink Extension not detecting links that start with `www`

[rockycodes]

autolink-java supports detecting WWW links, but the Autolink Extension for commonmark-java does not. This is easily fixed by removing this line so that the default detecting logic for autolink-java will be used. I am happy to submit a pr to do this, but wanted to first check if there is a historical reason for doing it this way since the more limited list seems to have been intentionally added in this change.

Fwiw, this is a blocker for me using the Autolink Extension in my project. If the more limited list of supported link types is intentional, it should be called out in the documentation.

Steps to reproduce the problem (provide example Markdown if applicable):

www.google.com

Expected behavior:

<a href="http://www.google.com" class="text-blue-600" target="_blank">www.google.com</a>

Actual behavior:

<p>www.google.com</p>

[robinst]

In bff088e4e2842f2eae40324b864d6a791fd653f0 the WWW mode didn't exist yet, that was only added in November 2016: https://github.com/robinst/autolink-java/pull/8#issuecomment-258745236.

So the reason is simply that it hasn't been added as an option to AutolinkExtension. I'd be happy for it to be added, yeah. You can copy how StrikethroughExtension does options (add a builder). And we would probably want our own enum instead of exporting autolink's.