Fixed code snippet in Cosmos DB README

[kafong123]

The code snippet included in the README doesn't match with the query in screenshot

Purpose

• There was a mismatch in documentation vs. screenshot. This PR intends to fix the discrepancy

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: