Links with IPv6 addresses cannot be handled correctly

[YihaoPeng]

Consider the following text:

Link with IPv6 address:
https://[2408:400a:d:a300::1]/

Link with IPv6 address and port:
https://[2408:400a:d:a300::1]:443/

The parsing result on https://parsedown.org/demo is:

<p>
  Link with IPv6 address:
  <a>https://[2408:400a:d:a300::1</a>]/
</p>
<p>
  Link with IPv6 address and port:
  <a href="https://[2408:400a:d:a300::1]/">https://[2408:400a:d:a300::1]:443/</a>
</p>

It should be:

<p>
  Link with IPv6 address:
  <a>https://[2408:400a:d:a300::1]/</a>
</p>
<p>
  Link with IPv6 address and port:
  <a href="https://[2408:400a:d:a300::1]/">https://[2408:400a:d:a300::1]:443/</a>
</p>