Allow for a maxTimeout when checking slow external links

[chris-dura]

When cross-linking to "external" websites, the website you're linking to may be extremely slow in returning a response. This results in some false failures being reported.

It would be good to allow for a max timeout or delay before reporting that the link is "dead".

An example site that I link to that always reports as "dead":

https://www.tobiidynavox.com/en-us/support-training/windows-control-2/