Update README for bindings db

[sunzhaochang]

Signed-off-by: sunzhaochang zhchsun1992@gmail.com

Description

Fix some errors in README for bindings db.

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• The quickstart code compiles correctly
• You've tested new builds of the quickstart if you changed quickstart code
• You've updated the quickstart's README if necessary
• If you have changed the steps for a quickstart be sure that you have updated the automated validation accordingly. All of our quickstarts have annotations that allow them to be executed automatically as code. For more information see mechanical-markdown. For user guide with examples see Examples.

[youngwookim]

Overall, Looks good!
A minor nit: change to the orders table should be change to the orders database WDYT?

[sunzhaochang]

@youngwookim Thanks for catching that. I will fix it.

[paulyuk]

LGTM