Use new up/down/left/right options

Examples-(vim).md

@@ -12,12 +12,12 @@ command! -nargs=1 Locate call fzf#run(
 ```vim
 " Open files in horizontal split
 nnoremap <silent> <Leader>s :call fzf#run({
-\   'tmux_height': '40%',
+\   'down': '40%',
 \   'sink': 'botright split' })<CR>
 
 " Open files in vertical horizontal split
 nnoremap <silent> <Leader>v :call fzf#run({
-\   'tmux_width': winwidth('.') / 2,
+\   'right': winwidth('.') / 2,
 \   'sink':  'vertical botright split' })<CR>
 ```
 
@@ -30,7 +30,7 @@ nnoremap <silent> <Leader>C :call fzf#run({
 \         "substitute(fnamemodify(v:val, ':t'), '\\..\\{-}$', '', '')"),
 \   'sink':    'colo',
 \   'options': '+m',
-\   'tmux_width': 20
+\   'left':    30
 \ })<CR>
 ```
 
@@ -52,7 +52,7 @@ nnoremap <silent> <Leader><Enter> :call fzf#run({
 \   'source':  reverse(<sid>buflist()),
 \   'sink':    function('<sid>bufopen'),
 \   'options': '+m',
-\   'tmux_height': '40%'
+\   'down':    len(<sid>buflist()) + 2
 \ })<CR>
 ```
 
@@ -102,7 +102,7 @@ command! FZFLines call fzf#run({
 \   'source':  <sid>buffer_lines(),
 \   'sink':    function('<sid>line_handler'),
 \   'options': '--extended --nth=3..',
-\   'tmux_height': '60%'
+\   'down':    '60%'
 \})
 ```