Python SDK placeholder examples incorrect

Examples given in the Queries & Placeholders section do not work, as they select ts.* from the airport collection, and the ts path does not exist.

Either needs to select * from the airport collection, or assign an alias ts to the airport namespace.

Related: the example for prepared statements needs to be placed in a separate file for re-use.

Reporter: Simon Dew
E-mail: simon.dew@couchbase.com