Fix the anchor regression

[reyang]

It seems 6522186 caused a regression with inline <a> links.

Trying to see if this is intentional, currently I've only included a unit test to discuss whether the behavior is intentional or not (without including the actual "fix").

[tcort]

markdown-link-check doesn't parse HTML, so it can't find #tomato in your test, but it is something I'm planning on adding.

[srl295]

@tcort do you have an issue tracking <a id=… (or <a name=…) parsing?

[sschuberth]

@tcort do you have an issue tracking <a id=… (or <a name=…) parsing?

I've created one at #195.