anchor link checks should support <a name="foo"></a>

[z1c0]

With the recently introduced anchor link check (which is great btw!) I encounter frequent errors when using explicit HTML-like anchors.

e.g.

...
Take me to [pookie](#pookie)
...
<a name="pookie"></a>
...

[nschonni]

Duplicate of https://github.com/tcort/markdown-link-check/issues/195