No explanation or example for the --size argument of split-pane

[tudorminator]

TerminalDocs/command-line-arguments.md

Please provide an explanation regarding the type of value that the --size argument takes and/or a usage example. For some reason I thought it might be a percentage of the window's width, but neither 40% nor 40 worked, only .4 did.

Thank you.

[mattwojo]

Add an example to reflect this value: 66afc3d

Thanks for contributing this suggestion @tudorminator!