This commit introduces the following changes to Alternator compability doc: * As of https://github.com/scylladb/scylladb/pull/11298 Alternator will return ProvisionedThroughput in DescribeTable API calls. We add the fact that tables will default to a BillingMode of PAY_PER_REQUEST (this wasn't made explicit anywhere in the docs), and that the values for RCUs/WCUs are hardcoded to 0. * Mention the fact that ScyllaDB (thus Alternator) hashing function is different than AWS proprietary implementation for DynamoDB. This is mostly of an implementation aspect rather than a bug, but it may cause user confusion when/if comparing the ResultSet between DynamoDB and Alternator returned from Table Scans. Refs: https://github.com/scylladb/scylladb/issues/11222 Fixes: https://github.com/scylladb/scylladb/issues/11315 Closes #11360