Markdown formatted URLs not properly detected as Safelinks URLs

[atc0005]

I encountered this today when attempting to use dslg to decode a formatted email.

This pattern decodes properly:

[placeholder](https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fatc0005%2Fsafelinks&data=data_placeholder&sdata=sdata_placeholder&reserved=0)

This pattern does not:

[https://github.com/atc0005/safelinks](https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fatc0005%2Fsafelinks&data=data_placeholder&sdata=sdata_placeholder&reserved=0)

The URL pattern within the URL anchor is enough to throw things off.

[atc0005]

Might be worth a look:

• https://github.com/yuin/goldmark

Dependencies used by this project are already using it, so it's already in the dependency tree.