Need a new layout strategy for more preview space.

[liangkarl]

Is your feature request related to a problem? Please describe.
I tried to create a new layout like bottom_pane, but it has different preview location.
If the original bottom_pane like blew,

     (file content)                                        (file content)

+--------------------+                                +--------------------+ 
|                    |                                |        |           |
|       Result       |                                | Result |  Preview  | 
|                    |    == (Toggle Preview) ==>     |        |           |
+--------------------+                                +--------------------+
|       Prompt       |                                |       Prompt       |
+--------------------+                                +--------------------+
       (bottom)                                              (bottom)

Then, what I'm trying to do is like this.

                                                           (file content)
                                                      +--------------------+ 
                                                      |                    |
    (file content)                                    |       Preview      |  
                                                      |                    |
+--------------------+                                +--------------------+ 
|                    |                                |                    |
|       Result       |                                |       Result       |  
|                    |    == (Toggle Preview) ==>     |                    |
+--------------------+                                +--------------------+
|       Prompt       |                                |       Prompt       |
+--------------------+                                +--------------------+
       (bottom)                                              (bottom)

This kind of layout is pretty common in some other nvim plugins like trouble, coc, etc, but I could not find out any similar layout in telescope.

Describe the solution you'd like
I have tried referenced vertiacal and bottom_pane to create a new layout strategy bottom_vertical in the layout_stragegies.lua. However, I'm suffering from the line and col settings. Also, I'm not sure if my implementation is proper for telescope, so I'd like to ask for some help in the community.

Describe alternatives you've considered

Additional context
A reference screenshot from coc is like this