Modify 'code-block' tag format so that the following python code
could be showed exactly, and reformat the more than 79 chars of lines.
Change-Id: Ic6721e4cc8f4c7a3e4a7c7dbd63d9089180cdc33
Add a developer guideline for command options to define the options
used across multiple commands and make them behave consistently.
Change-Id: I1dbbafe8061e10b271cd55cac056731508c52204