Close buffer along with window

[tamton-aquib]

In case of floats:
the window is closed, but the buffer is not completely wiped.

buflist contained this buffer:

I tried adding a line to `closeCmd()` inside `createWin()`:

and it was temporarily fixed, but i dont know if it breaks anything else 😅

[is0n]

It doesn't seem to break anything so I've updated the code to include vim.api.nvim_buf_delete(M.buf, {force = true}).

Tested it out with stabline and it seems to work. Thanks for pointing this out!