Get the size of terminal {buf}. Returns a list with two numbers: [rows, cols]. This is the size of the terminal, not the window containing the terminal.

{buf} must be the buffer number of a terminal window. Use an empty string for the current buffer. If the buffer does not exist or is not a terminal window, an empty list is returned.

Can also be used as a method:

GetBufnr()->term_getsize()