Replace linkify-urls with linkifyjs

[PVince81]

Linkify-urls is redundant as we already had a library.
Linkify-urls is not compatible with Safari as it's designed to be used
on Node JS and it uses non-polyfillable regexp features.

@nickvergessen please test this with Safari, also with Talk.

[nickvergessen]

Works

[dartcafe]

Is it a good idea to replace a 7kb dependency with a >500kb one?
Just mentioning: #1488
And linkify-urls@2 works great, also in Safari.

[nickvergessen]

Linkify is already a dependency.
And at least the current linkify-urls causes a parse error on safari, which is why Talk and the vue lib docs are not working on recent safari

[PVince81]

so far, as this is mostly fire fighting, I'd like to move forward with this fix and not use two different libraries.

separately we could look into finding a smaller library then and use only that one everywhere

I think @dartcafe was referring to the old version of linkify-urls which doesn't seem to have the back-references in the regexp https://github.com/sindresorhus/linkify-urls/blob/v2.2.0/index.js#L5 vs https://github.com/sindresorhus/linkify-urls/blob/2d04fd8121e6adc33d35f1303495966a39f0dfa8/index.js#L5.
But I'm not sure if we'll want to use an outdated / old major of a library. Maybe there's yet another library that would fit.
This will need further research.

[PVince81]

I've raised #1679 for researching a smaller dep that works everywhere

[skjnldsv]

SO, what was the decision regarding #1488 ?
Because linkifyjs uses jQuery and is quite heavy for a simple string replacement.

[PVince81]

follow up in #1488

there was no further discussion about it.

my PR was just an emergency thing to unblock a release due to Safari regressions