Option to put plot pane below script by default

[heavywatal]

Is your feature request related to a problem? Please describe. The desired layout is like this:

|--------|--------|
| script |        |
|--------|terminal|
|  plot  |        |
|--------|--------|

AFAIK, this cannot be achieved without manual adjustment "View > Editor Layout > Two Rows" after plot() because the plot pane always shows up in two-column editor layout like this:

|--------|--------|
|scr |pl |        |
|ipt |ot |terminal|
|    |   |        |
|--------|--------|

Describe the solution you'd like If there is a way to achieve the desired layout at once, it should be documented. If not, this extension should get a new option like r.plot.layout = "TwoRows".

Describe alternatives you've considered Do "View > Editor Layout > Two Rows" every time I plot.

This is not a duplicate of #848 because the output pane is irrelevant here.

"Terminals in editor area" is not the solution because it is more time-consuming than "View > Editor Layout > Two Rows".

Additional context The layout is demonstrated in the official doc https://code.visualstudio.com/docs/languages/r.