Add tag-blocks text object support?

[wting]

Is it possible to add tag-blocks support?

I'm opening a separate issue from #14 because that one is referring to 3rd party text objects.

[wellle]

That's a good idea!

I will look into it.

[wellle]

Implemented in #46. Thank you!

New text objects:

it  at  It  At
int ant Int Ant
ilt alt Ilt Alt

They behave exactly like pair text objects. (accept counts and support multi line seeking)

[wting]

Thanks for the quick turnaround and an awesome plugin!