documentation: layouts

[vlappa]

Is it me, or are the available layouts not documented? Hard to find at least it seems.

man tmux says:

The following layouts are supported:

 even-horizontal
         Panes are spread out evenly from left to right across the window.

 even-vertical
         Panes are spread evenly from top to bottom.

 main-horizontal
         A large (main) pane is shown at the top of the window and the remaining panes are spread
         from left to right in the leftover space at the bottom.  Use the main-pane-height window
         option to specify the height of the top pane.

 main-vertical
         Similar to main-horizontal but the large pane is placed on the left and the others spread
         from top to bottom along the right.  See the main-pane-width window option.

 tiled   Panes are spread out as evenly as possible over the window in both rows and columns.

[tony]

I am fine with adding this to the docs, if there's a PR.