bug: Split layout p1 values reversed

[nikisix]

I have to set p1 to .4 in order to get the file content percentage to .6.
Should be an easy fix. I might take a look at fixing later if I have time.

Example below:

" ###### Split layout
" ```vim
" You can define a custom split layout as a dictionary, the default is:
let g:jukit_layout = {
    \'split': 'horizontal',
    \'p1': 0.4,
    \'val': [
        \'file_content',
        \{
            \'split': 'vertical',
            \'p1': 0.4,
            \'val': ['output', 'output_history']
        \}
    \]
\}

" this results in the following split layout:
"  ______________________________________
" |                      |               |
" |                      |               |
" |                      |               |
" |                      |               |
" |                      |     output    |
" |                      |               |
" |                      |               |
" |    file_content      |               |
" |                      |_______________|
" |                      |               |
" |                      |               |
" |                      | output_history|
" |                      |               |
" |                      |               |
" |______________________|_______________|