Fix the wording for the example part

"The following example creates a set of primary and secondary indexes on the beer-sample bucket with the defer_build option. After the create index statement comes back, system:indexes is queried to for the status of the index."

needs to be changed, because the example does not create a primary index. It only creates a secondary index definition. So the text can be changed to

"The following example creates a secondary index on the beer-sample bucket with the defer_build option. After the CREATE INDEX statement comes back, system:indexes is queried to for the status of the index."