How about add a feature? multiple tab terminal

[R66]

hi, toggle-terminal is a great vim plugin. i love it.
how about add this feature, that's split multi tab in toggle-terminal buffer,
each tab has a terminal job, you can new a tab and close it, i think it's a
nice feature.

[Tairi Chiba]

Looks very good, but I don't use this plugin long time.
Pull request welcome😉