RFC: SQL partitioning entering final comment period

The SQL partitioning RFC is entering final comment period. Please leave comments on the PR!

For easy reference, the RFC summary is reproduced below:

Table partitioning provides row-level control over how and where data is stored.

Specifically, CREATE TABLE, ALTER TABLE, and their INDEX counterparts
learn to accept a partition specification, which maps ranges of the index to
named partitions. Zone configs learn to target these partitions so that locality
constraints and replication settings can vary per partition instead of per table
or database.