Improve readme

[chenrujun]

Purpose

• Use table to display the 2 branches. Because table make it clearer.
• Fix error about "Run sample project".

Does this introduce a breaking change?

[ ] Yes
[x] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[x] Documentation content changes
[ ] Other... Please describe:

[chenrujun]

Hi, @stliu .
Please help to review this PR when you have time.