Refactor schema-design guide

Introduce some long-overdue changes to the schema design guide. In
particular, more content on adding and dropping range partitions, as
well as a better introduction to how to analyze partitioning strategies.

Change-Id: If4d91043d72e816a930d50927bf9441bd6b30b9b
Reviewed-on: http://gerrit.cloudera.org:8080/4485
Tested-by: Kudu Jenkins
Reviewed-by: Alexey Serbin <aserbin@cloudera.com>
(cherry picked from commit 64ec121498f603fb3c4e5291f5a43eac2bcd0f8f)
Reviewed-on: http://gerrit.cloudera.org:8080/4680
Reviewed-by: Dan Burkert <dan@cloudera.com>
Tested-by: Dan Burkert <dan@cloudera.com>
6 files changed