Handle empty tags meta and correct documentation about nico

[kavinyao]

I suppose using comma as delimiter is preferred as the user may want to use more than one word as a tag, e.g. "cool projects". Although this situation can be avoided with "cool-projects".

[lepture]

@kavinyao comma is the right way.

[kavinyao]

Thanks for the quick fix about the second problem. What about the first problem?

[kavinyao]

Awesome! 😃