http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html#option-lists
RST only accepts two forms for option argument:
- Begins with a letter and consists of [a-zA-Z0-9_].
- Begins with "<" and ends with ">"; any characters except angle
brackets are allowed internally.
Updated documents to obey the above rule.
Also cleaned up the documents to follow the syntaxes defined in
http://docopt.org/.
Change-Id: I06c6fa6db524325373053b26fc99169469664f01
KongQun Yang