doc: translate each section in "load"

refs #1661

In previous commit message, I said "including arguments (it is wrong,
"parameters" correctly) in Syntax", but I separate them because of few
many parameters.
doc: re-arrange the order of sections in "load" command document

Before:          After:
  Syntax           Summary
  Summary          Syntax
  Parameters       Parameters
  Return value     Usage
  Usage            Return value
  See also         See also