Doc style:
* use tildes for heading 2 (following the rst convention);
* break source lines exceeded 79 characters (rst convention);
* remove unneccessary blank lines:
* 4 blank lines between sections;
* 2 blank lines between sub-sections;
* 1 blank line between paragraphs in a section/subsection;
* no blank lines at the bottom of a source file.
* add a space after commas in the middle of a line;
Instances API:
* change the order to match the description at the begin;
* add "Update instance name";
* add "Upgrade datastore version".
Change-Id: I3520e42f6ad97cb30632cf05241cec316409c9be
Signed-off-by: Zhao Chao <zhaochao1984@gmail.com>
b0577ae97e